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Abstract: Currently there is no approved medicine for the treatment of metabolic syndrome. A series of new derivatives of berberine (BBR) or pseudoberberine (1) was synthesized and evaluated for their activity on AMP-activated protein kinase (AMPK) activation and up-regulatory low-density-lipoprotein receptor (LDLR) gene expression, respectively. In addition, the four major metabolites of BBR in vivo were also examined for their activity on AMPK in order to further understand the chemical mechanisms responsible for its glucose-lowering efficacy. Among those BBR analogues, compound 1 exhibited the potential effect on AMPK activation and LDLR up-regulation as compared with BBR. The results suggested that compound 1 might be a multiple-target agent for the treatment of metabolic syndrome, and thus was selected as a promising drug candidate for further development. [Copyright &y& Elsevier]

Conclusions: Computed tomography (CT) scan with three-dimensional (3D) reconstruction of the inner ear provides a more accurate image of the relationship of the electrode within the cochlear canal, with direct demonstration of electrode insertion depth in the cochlea in comparison with X-ray plain film. Objective: This study was designed to evaluate the value of spiral CT scans with 3D reconstruction in determining the insertion site and depth of implanted cochlear implant electrodes. Methods: A total of 172 cochlear implant recipients were involved in this study. The implanted electrodes of all patients were examined by X-ray plain film, and 157 cochlear recipients were examined by spiral CT scans with axial 1 mm image slices. The data from the CT scans were transferred to a workstation for 3D reconstruction (direct volume rendering) of the inner ear. The pseudocolor technique was used to display the electrode. Results: The insertion depth of the electrode could be evaluated indirectly by the X-ray plain film. In contrast, the stereoscopic images from a CT scan with 3D reconstruction of the inner ear demonstrated the shape, position, and insertion depth of the electrode more accurately [ABSTRACT FROM AUTHOR]

Conclusion: A better animal model of autoimmune inner ear disease (AIED) in Sprague-Dawley rats has been developed by combination with high dose of pertussis toxin. This study also indicated that inner ear-specific antigens can be involved in autoimmune reactions. Cell-mediated immune injury can play an important role in the induction of AIED, at least in the earlier stage. Objectives: The purpose of this study was to develop a more suitable rat model that demonstrated closer resemblance to the pathophysiological process in AIED. Methods: Ninety-six female Sprague-Dawley rats were divided into four groups. They were subcutaneously immunized with crude inner ear antigen/complete Freund's adjuvant (CIEAg/CFA), or intraperitoneal injection of 500 ng pertussis toxin (PT), or injection of CIEAg/CFA++PT, or phosphate-buffered saline (PBS) alone. The auditory function, histopathology of the inner ear, and autoantibodies were examined. Results: Significant differences in the time course of auditory brainstem response (ABR) threshold and mean score of cellular infiltration were demonstrated in the CIEAg/CFA++PT group of animals. Missing hair cells, degeneration of the spiral ganglion cells, endolymphatic hydrops, and autoantibodies were all noted after immunization. There were no significant differences in ABR threshold or histopathology in any other group of animals. [ABSTRACT FROM AUTHOR]

Abstract: Our previous studies proved that berberine (BBR) up-regulates the insulin receptor (InsR) gene by stimulating its promoter and calphostin C blocks this effect. Here, the present study was designed to discover the specific kinase isoform(s) used by berberine. In the blocking experiment, we found that Gö6976, a kinase inhibitor that potently inhibit PKCμ/protein kinase D 1 (PKD1), effectively and specifically reduced the activity of BBR on InsR. PKD1/PKCμ is a member of the PKD family that also covers PKD2 and PKD3/PKCν with high homology. The role of PKD1 in InsR expression was also proved by using another PKD-activator oligomycin. In the RNA interference experiment, we found that the effects of BBR on InsR expression and on cellular glucose consumption were partially eliminated by silencing any one of the three PKDs and were totally abolished by silencing all of them. BBR enhanced the PKD1 catalytic activity, but not its expression. Along with BBR treatment, PKD1 ser916 autophosphorylation was increased time- and dose-dependently, indicating an activation of PKD1 by BBR. BBR also induces PKD1 translocation from cytosol-to-plasma membrane, further verifying the activation of PKD1. These results suggest that the PKD family is involved in the transcriptional regulation of the InsR gene; we consider it to be a potential new target to discover drugs for sugar-related disorders in the future. [ABSTRACT FROM AUTHOR]

Abstract: Molecular biological studies and electrophysiological data have demonstrated that acetylcholine (ACh) is the principal cochlear and vestibular efferent neurotransmitter among mammalians. However, the functional roles of ACh in type II vestibular hair cells (VHCs II) among mammalians are still unclear, with the exception of the well-known α9-containing nicotinic ACh receptor (α9-containing nAChR)-activated small conductance, calcium-dependent potassium current (SK) in cochlear hair cells and frog saccular hair cells. The activation of SK current was necessary for the calcium influx through the α9-containing nAChR. Recently, we have demonstrated that ACh-induced big conductance, calcium-dependent potassium current (BK) was present in VHCs II of the vestibular end-organ of guinea pig. In this study, the nature of calcium influx for the activation of ACh-induced BK current in saccular VHCs II of guinea pig was investigated. Following extracellular perfusion of ACh, saccular VHCs II displayed a sustained outward current, which was sensitive to iberiotoxin (IBTX). High concentration of apamin failed to inhibit the current amplitude of ACh-induced outward current. Intracellular application of Cs+ completely abolished the current evoked by ACh. ACh-induced current was potently inhibited by nifedipine, nimodipine, Cd2+ and Ni2+, respectively. The inhibition potency of these four calcium channel antagonists was nimodipine>nifedipine>cadmium>nickel. The L-type Ca2+ channels agonist, (−)-Bay-K 8644 mimicked the effect of ACh and activated an IBTX-sensitive current. In addition, partial VHCs II displayed a biphasic waveform. In conclusion, the present data showed that in the guinea pig saccular VHCs II, ACh-induced BK channel was coupled with the calcium channel, but not the receptor. The perfusion of ACh will drive the opening of calcium channels; the influx of calcium ions will then activate the BK current. [Copyright &y& Elsevier]

Abstract: Hair cells of inner ear are suggested to be inhibited by the activation of the α9-containing nicotinic acetylcholine (ACh) receptors (α9-containing nAChRs). Several studies have suggested that the native nicotinic-like ACh receptors (nAChRs) in hair cells display a significant permeability of Ca2+ ions and unusual pharmacological properties. The activation of native nAChRs will initiate the hyperpolarization of hair cells by activation of the small conductance, Ca2+-activated K+ channels (SK). In this work, the properties of the ACh-sensitive potassium current (IK(ACh)) in outer hair cells (OHCs) of guinea pigs were investigated by employing whole-cell patch-clamp. Followed by perfusion of ACh, OHCs displayed a rapid desensitized current with an N-shaped current–voltage curve (I–V) and a reversal potential of − 66 ± 7 mV. The IK(ACh) was still present during perfusion of either iberiotoxin (IBTX, 200 nM) or TEA (5 mM) but was potently inhibited by apamin (1 μM), TEA (30 mM). The IK(ACh) demonstrated a strong sensitivity to α-bungarotoxin (α-BgTx), bicuculline and strychnine. These results suggested that OHCs display the well-known SK current, which might be gated by the α9-containing nAChRs. Two important changes were present after lowering the Ca2+ concentration in the external conditions from 2 mM to 0.2 mM: one was a flattened N-shape I–V relationship with a maximum shifted toward hyperpolarized potentials from −20 ∼ −30 mV ∼ −40 to −50 mV, the other was a significant reduction in the agonist maximal response (percentage of maximal response 10.5 ± 5.4). These results indicated that native nAChRs are both permeable to and modulated by extracellular Ca2+ ions. Taken together, this work provides direct evidences that SK channels in OHCs of guinea pigs are gated by α9-containing nAChRs, which play an important role in the fast cholinergic efferent inhibition. This fast inhibition is both potently dependent on the permeability of Ca2+ ions through the native nAChRs and modulated by Ca2+ ions. [Copyright &y& Elsevier]

Abstract: Since,d-galactose (d-gal) overload model has been used as a premature aging model, we hypothesized that it may also lead to accelerated aging in the inner ear. Furthermore, though the mitochondrial DNA (mtDNA) 4834bp deletion mutation has been considered as the marker of aging, there is no information available in the literature concerning the mtDNA 4834bp deletion mutation condition of the d-gal induced premature aging model. We investigate the changes in inner ear enzymatic activity, the occurring of mtDNA 4834bp deletion in inner ear and other tissues and the relating hearing thresholds after the administration of high dosage (150mg/kg per day) and low dosage (50mg/kg per day) of d-gal to rats. Furthermore, the incidence of the mtDNA 4834bp deletion in different tissues as well as in blood sample was compared. The results showed that daily subcutaneous injections of d-gal into rats for 8 weeks could lead to the biochemical defects and mtDNA 4834bp deletion in the inner ear tissue and other tissues, which represent the typical aging animals, but the relating hearing threshold shifts (TS) were nearly identical in the three groups. This study also indicates that using of blood samples to detect mtDNA 4834bp deletion in clinical research might lead to a ‘false negative’ result. A higher sensitive result could be gained using tissue biopsy to examine mtDNA 4834bp deletion. [Copyright &y& Elsevier]

Abstract: Mutations in mitochondrial DNA (mtDNA) are associated with diverse pathological states in humans, notably sensorineural deafness. In humans, mtDNA4977 deletion, known as common deletion, is thought to play a critical role in presbyacusis. A similar mtDNA deletion occurs in the naturally aging rats is mtDNA4834 deletion. Today, it is still obscure about the effect of common mtDNA deletion on the presbyacusis and hearing loss. We establish a model of rat associated with mtDNA4834 deletion in inner ear by d-galactose. It was found that the malondialdehyde (MDA) increased with superoxide dismutase (SOD) decreasing in the inner ear of the rat treated with d-galactose than of the control. However, there was no significant difference in elevation of ABR threshold between the rat with mtDNA4834 deletion induced by d-galactose and control. After aminoglycoside antibiotic injected, the hearing threshold of the rats carrying mtDNA4834 deletion increased significantly compared with the rats without mtDNA4834 deletion. The results show that resembled accelerated aging in the inner ear of the rat could be induced by injecting d-galactose. Moreover, those suggest that mtDNA4834 deletion can not directly induce the hearing loss, but acting as a predisposing factor which can greatly enhance the sensitivity of the inner ear to the aminoglycoside antibiotic. [Copyright &y& Elsevier]

Abstract: Molecular biological studies have demonstrated that both muscarinic receptor subtypes and nicotinic receptor subunits were located in mammalian vestibular sensorineural epithelium. However, the functional roles are still unclear, with the exception of the well-known α9-containing nicotinic ACh receptor (α9nAChR). In this study, the properties of acetylcholine (ACh)-induced currents were investigated by whole-cell patch clamp technique in isolated type II vestibular hair cells (VHCs II) of guinea pig. VHCs II displayed a sustained, non-inactivating current when extracellular application of ACh. ACh-induced currents restored gradually and it took about 60 s to get a complete recovery. ACh-induced current was not affected by extracellular Na+, but strongly affected by extracellular K+ and Ca2+. Depletion of the intracellular Ca2+ stores by intracellular application of inositol 1,4,5-trisphosphate (IP3) or blocking of the release of intracellular Ca2+ stores by intracellular application of heparin failed to inhibit this current. ACh-induced currents were inhibited by nifedipine, Cd2+, tetraethylammonium (TEA), charybdotoxin (CTX), iberiotoxin (IBTX), atropine and d-tubocurarine (DTC), respectively, but not by apamin. In conclusion, ACh stimulates a large conductance, Ca2+-activated K+ current (BK) in guinea pig VHCs II by activation of the influx of Ca2+ ions, which is mediated by an ACh receptor that could not be defined to be the odd-number muscarinic receptor. [Copyright &y& Elsevier]

Berberine (BBR) is a multi-target drug (MTD) that has proven effective in the treatment of metabolism-related chronic diseases (CDs). However, the mode of action (MOA) of BBR remains to be clarified. At a cellular level, the inhibitory effect of BBR on mitochondrial enzymes is probably responsible for many of its biological activities, including the activation of low-density lipoprotein receptor (LDLR), AMP-activated protein kinase (AMPK) and insulin receptor (InsR); these biological activities contribute to ameliorate peripheral blood metabolic profiles, e.g. by reducing plasma lipids and glucose levels, thus improving signs and symptoms of metabolic disorders. In this perspective, BBR acts as a targeted therapy. However, it also exerts pleiotropic systemic activities on some root causes of CDs that include antioxidant / anti-inflammatory effects and modifications of gut microbiota composition and metabolism, which may also contribute to its disease-modifying effects. After reviewing the different MOA of BBR, here we propose that BBR acts through a drug-cloud (dCloud) mechanism, as different to a drug-target effect. The dCloud here is defined as a group of terminal molecular events induced by the drug (or/and related metabolites), as well as the network connections among them. In this scenario, the therapeutic efficacy of BBR is the result of its dCloud effect acting on symptoms/signs as well as on root causes of the diseases. The dCloud concept is applicable to other established MTDs, such as aspirin, metformin, statins as well as to nutrient starvation, thus providing a novel instrument for the design of effective therapies against multifactorial metabolism-related CDs. [ABSTRACT FROM AUTHOR]

The GJB2 gene, encoding Connexin26 (Cx26), is one of the most common causes of inherited deafness. Clinically, mutations in GJB2 cause congenital deafness or late‐onset progressive hearing loss. Recently, it has been reported that Cx26 haploid deficiency accelerates the development of age‐related hearing loss (ARHL). However, the roles of cochlear Cx26 in the hearing function of aged animals remain unclear. In this study, we revealed that the Cx26 expression was significantly reduced in the cochleae of aged mice, and further explored the underlying molecular mechanism for Cx26 degradation. Immunofluorescence co‐localization results showed that Cx26 was internalized and degraded by lysosomes, which might be one of the important ways for Cx26 degradation in the cochlea of aged mice. Currently, whether the degradation of Cx26 in the cochlea leads directly to ARHL, as well as the mechanism of Cx26 degradation‐related hearing loss are still unclear. To address these questions, we generated mice with Cx26 knockout in the adult cochlea as a model for the natural degradation of Cx26. Auditory brainstem response (ABR) results showed that Cx26 knockout mice exhibited high‐frequency hearing loss, which gradually progressed over time. Pathological examination also revealed the degeneration of hair cells and spiral ganglions, which is similar to the phenotype of ARHL. In summary, our findings suggest that degradation of Cx26 in the cochlea accelerates the occurrence of ARHL, which may be a novel mechanism of ARHL. [ABSTRACT FROM AUTHOR]

Few studies have assessed factors influencing the rate and speed of good outcomes in cochlear implantation (CI) children. To analyse the factors influencing the rate and speed of available communication in CI children. The study involved 316 children. The categories of auditory performance (CAP) and speech intelligibility rating (SIR) were used to evaluate outcomes. Multivariable proportional Cox regression models were established to analyse the effect of preoperative factors. Five variables were entered into the three multivariable models of CAP ≥6, SIR ≥4 and concurrent CAP ≥6 and SIR ≥4. Older age at implantation was a significant poor factor in the three models with estimated hazard ratios (HRs) of.541,.629, and.554, respectively. Another negative factor was poor parental literacy for the three outcomes (HR.639,.638, and.542, respectively). More than 3 months of rehabilitation from institutes had a positive effect on CAP ≥6 and concurrent CAP ≥6 and SIR ≥4 (HR 1.626 and 1.667, respectively). Older age at implantation and poor parental literacy were negative factors. Receiving regular rehabilitation from institutes pre-CI could help the children gain available communication ability earlier on. [ABSTRACT FROM AUTHOR]

Meniere's disease (MD) represents one of the vertigo disorders characterized by triad symptoms (recurrent vertigo, fluctuating hearing loss, tinnitus or ear fullness). The diagnosis of MD relies on the accurate and detailed taking of medical history, and the differentiation between MD and vestibular migraine (VM) is of critical importance from the perspective of the treatment efficacy. VM is a highly prevalent vertigo condition and its typical symptoms (headache, vestibular symptoms, cochlear symptoms) mimic those of MD. Furthermore, the misdiagnosis in MD and VM could lead to VM patients mistakenly receiving the traumatic treatment protocol designed for MD, and sustaining unnecessary damage to the inner ear. Fortunately, thanks to the advances in examination technologies, the barriers to their differentiation are being gradually removed. These advances enhance the diagnostic accuracy of vertigo diseases, especially VM and MD. This review focused on the differentiation of VM and MD, with an attempt to synthesize existing data on the relevant battery of differentiation diagnosis (covering core symptoms, auxiliary tests [audiometry, vestibular tests, endolymphatic hydrops tests]) and longitudinal follow-up. Since the two illnesses are overlapped in all aspects, no single test is sufficiently specific on its own, however, patterns containing all or at least some features boost specificity. [ABSTRACT FROM AUTHOR]

(1) Background: Vestibular migraine (VM) and Menière's disease (MD) share multiple features in terms of clinical presentations and auditory-vestibular functions, and, therefore, more accurate diagnostic tools to distinguish between the two disorders are needed. (2) Methods: The study was of retrospective design and examined the data of 69 MD patients, 79 VM patients and 72 MD with migraine patients. Five vestibular autorotation test (VAT) parameters, i.e., horizontal gain/phase, vertical gain/phase and asymmetry were subjected to logistic regression. The receiver operating characteristic (ROC) curves were generated to determine the accuracy of the different parameters in the differential diagnosis of MD and VM. (3) Results: Our results showed that the horizontal gain of VAT significantly outperformed other parameters in distinguishing MD and VM. In addition, the sensitivity, specificity and accuracy of the horizontal gain were 95.7%, 50.6% and 71.6%, respectively, for the differentiation between VM and MD. In most MD patients, the horizontal gain decreased in the range of 3–4 Hz, while in most VM patients, horizontal gain increased in the range between 2–3 Hz. More MD with migraine patients had an increased horizontal gain when the frequency was less than 5.0 Hz and had a decreased horizontal gain when the frequency was greater than 5.0 Hz. (4) Conclusion: Our study suggested the VAT, especially the horizontal gain, as an indicator, may serve as a sensitive and objective indicator that helps distinguish between MD and VM. Moreover, VAT, due to its non-invasive and all-frequency nature, might be an important part of a test battery. [ABSTRACT FROM AUTHOR]

Recent studies have revealed the significant role of the competing endogenous RNA (ceRNA) network in human diseases. However, systematic analysis of the ceRNA mechanism in chronic rhinosinusitis with nasal polyps (CRSwNP) is limited. In this study, we constructed a competitive endogenous RNA (ceRNA) network and identified a potential regulatory axis in CRSwNP based on bioinformatics analysis and experimental verification. We obtained lncRNA, miRNA, and mRNA expression profiles from the Gene Expression Omnibus. After analysis of CRSwNP patients and the control groups, we identified 565 DE-lncRNAs, 23 DE-miRNAs, and 1799 DE-mRNAs by the DESeq2 R package or limma R package. Enrichment analysis of 1799 DE-mRNAs showed that CRSwNP was associated with inflammation and immunity. Moreover, we identified 21 lncRNAs, 8 miRNAs and 8 mRNAs to construct the lncRNA-miRNA-mRNA ceRNA network. A potential MIAT/miR-125a/IRF4 axis was determined according to the degree and positive correlation between a lncRNA and its competitive endogenous mRNAs. The GSEA results suggested that IRF4 may be involved in immune cell infiltration. The validation of another dataset confirmed that MIAT and IRF4 were differentially expressed between the CRSwNP and control groups. The area under the ROC curve (AUC) of MIAT and IRF4 was 0.944. The CIBERSORT analysis revealed that eosinophils and M2 macrophages may be involved in the CRSwNP process. MIAT was correlated with dendritic cells and M2 macrophages, and IRF4 was correlated with dendritic cells. Finally, to validate the key genes, we performed in-silico validation using another dataset and experimental validation using immunohistochemistry, immunofluorescence, and Western blot. In summary, the constructed novel MIAT/miR-125a/IRF4 axis may play a critical role in the development and progression of CRSwNP. We believe that the ceRNA network and immune cell infiltration could offer further insight into novel molecular therapeutic targets for CRSwNP. [ABSTRACT FROM AUTHOR]

Genetic alterations in the cell cycle pathway are common in head and neck squamous cell carcinoma (HNSCC). We identified four novel HNSCC susceptibility loci (CDKN1C rs452338, CDK4 rs2072052, E2F2 rs3820028 and E2F2 rs2075993) through a two-stage matched case–control study. There was a combined effect among the four single nucleotide polymorphisms (SNPs), as the number of risk genotypes increased, the risk of HNSCC displayed an increasing trend (P trend < 0.001). And there were multiplicative interactions between rs452338 and rs2072052, rs2072052 and rs3820028, rs2072052 and rs2075993. Functional bioinformatics analysis and dual-luciferase reporter assay revealed that E2F2 rs2075993 T>C reduced the stability of E2F2 3'-UTR secondary structure and affected the binding of E2F2 to miR-940, which was up-regulated in HNSCC tumor tissues (P = 2.9e−8) and was correlated with poor overall survival of HNSCC (HR = 1.39, 95% CI = 1.02–1.90). In vitro assays, we discovered that the expression of miR-940 was regulated by METTL3 , and miR-940 promoted the proliferation, migration and invasion, and inhibited the senescence and autophagy of tumor cells. In terms of mechanism, compared with rs2075993 allele T, we found that the protective variant rs2075993 allele C interfered with the translational inhibition of E2F2 by miR-940, resulting in increased expression of E2F2 protein, which further reduced the proliferation, migration, invasion, and increased the senescence of tumor cells. [ABSTRACT FROM AUTHOR]

Conclusion. A trans-superior meatus endoscopic approach to treat diseases in the sphenoid sinus and sellar area is a safe, minimally traumatic, and effective method. Objective: To avoid complications, we explored the use of the superior meatus and superior turbinate in the endoscope approach to the sphenoid sinus and sellar area. Patients and methods. This was a retrospective analysis of the curative effect of the trans-superior meatus approach for diseases in the sphenoid sinus and sellar area in 138 cases. Results. All of 138 patients had successful operations and no serious complication occurred. All cases were followed up for a period of 1-3 years. No recurrence was found in 94 patients with isolated sphenoid sinus disease (sinusitis, mucoceles, or mycosis). Of 24 patients with pituitary adenoma, 17 patients had entire resection and no recurrence was found. Four patients had subtotal resection and three patients had partial resection with postoperative radiotherapy, and preoperative symptoms were improved. Of 13 cases of cerebrospinal rhinorrhea in the sphenoid sinus, 12 cases were successfully repaired by a single operation and 1 case was successfully repaired by a repeat operation. Among seven cases with decompression of the optic canal, four had obvious effect, two cases showed improvement, and there was no improvement in one case. [ABSTRACT FROM AUTHOR]

Congenital deafness is one of the most common causes of disability in humans, and more than half of cases are caused by genetic factors. Mutations of the MYO15A gene are the third most common cause of hereditary hearing loss. Using next-generation sequencing combined with auditory tests, two novel compound heterozygous variants c.2802_2812del/c.5681T>C and c.5681T>C/c.6340G>A in the MYO15A gene were identified in probands from two irrelevant Chinese families. Auditory phenotypes of the probands are consistent with the previously reported for recessive variants in the MYO15A gene. The two novel variants, c.2802_2812del and c.5681T>C, were identified as deleterious mutations by bioinformatics analysis. Our findings extend the MYO15A gene mutation spectrum and provide more information for rapid and precise molecular diagnosis of congenital deafness. [ABSTRACT FROM AUTHOR]

Central presbycusis is caused by degradation of the auditory centre during ageing. Its main characteristics are difficulties in understanding language and localizing sound. Presbycusis is an increasingly critical public health problem, but the underlying molecular mechanism has not been fully elucidated. Ferroptosis is a form of regulated cell death caused by iron‐ and reactive oxygen species‐induced lipid peroxidation. Ferroptosis is related to many pathological processes, but whether it participates in the degeneration of the auditory system remains unclear. To investigate this, we measured iron levels in a simulated ageing model established by the addition of d‐galactose (d‐gal). We found, for the first time, that iron accumulated within cells and that the ultrastructural features of ferroptosis appeared in the auditory cortex with ageing. These changes were accompanied by upregulation of iron regulatory protein 2 (IRP‐2), which led to an increase in transferrin receptor 1 (TfR‐1), thus increasing iron entry into cells and potentially leading to ferroptosis. In addition, the malondialdehyde (MDA) content and the occurrence of mitochondrial DNA common deletions (CDs) increased, neuron degeneration appeared, and glutathione (GSH) and superoxide dismutase (SOD) activity decreased. Furthermore, we found that treatment with the iron chelator deferoxamine (DFO) and knockdown of IRP‐2 both relieved ferroptosis during the simulated ageing process, thus achieving a partial protective effect to delay ageing. In summary, we describe here the first discovery that age‐related iron deposition and ferroptosis may be associated with auditory cortex neurodegeneration. Relieving ferroptosis might thus be a new intervention strategy for age‐related hearing loss. [ABSTRACT FROM AUTHOR]

Waardenburg syndrome (WS), also known as auditory-pigmentary syndrome, is the most common cause of syndromic hearing loss. It is responsible for 2–5% of congenital deafness. WS is classified into four types depending on the clinical phenotypes. Currently, pathogenic mutation of PAX3, MITF, EDNRB, EDN3, SNAI2, or SOX10 can cause corresponding types of WS. Among them, SOX10 mutation is responsible for approximately 15% of type II WS or 50% of type IV WS. We report the case of a proband in a Chinese family who was diagnosed with WS type II. Whole exome sequencing (WES) of the proband detected a novel heterozygous spontaneous mutation: SOX10 c.246delC. According to analysis based on nucleic acid and amino acid sequences, this mutation may produce a truncated protein, with loss of the HMG structure domain. Therefore, this truncated protein may fail to activate the expression of the MITF gene, which regulates melanocytic development and plays a key role in WS. Our finding expands the database of SOX10 mutations associated with WS and provides more information regarding the molecular mechanism of WS. [ABSTRACT FROM AUTHOR]

Jervell and Lange-Nielsen syndrome (JLNS) is a rare but severe autosomal recessive disease characterized by profound congenital deafness and a prolonged QTc interval (greater than 500 milliseconds) in the ECG waveforms. The prevalence of JLNS is about 1/1000000 to 1/200000 around the world. However, exceed 25% of JLNS patients suffered sudden cardiac death with kinds of triggers containing anesthesia. Approximately 90% of JLNS cases are caused by KCNQ1 gene mutations. Here, using next-generation sequencing (NGS), we identified a compound heterozygosity for two mutations c.1741A>T (novel) and c.477+5G>A (known) in KCNQ1 gene as the possible pathogenic cause of JLNS, which suggested a high risk of cardiac events in a deaf child. The hearing of this patient improved significantly with the help of cochlear implantation (CI). But life-threatening arrhythmias occurred with a trigger of anesthesia after the end of the CI surgery. Our findings extend the KCNQ1 gene mutation spectrum and contribute to the management of deaf children diagnosed with JLNS for otolaryngologists (especially cochlear implant teams). [ABSTRACT FROM AUTHOR]

Auditory neuropathy spectrum disorder (ANSD), also called auditory neuropathy (AN), is a unique type of prelingual hearing impairment. Up to 10% of deaf infants and children are affected by this disease. Mutation of the OTOF gene which encodes otoferlin is the common cause of congenital nonsyndromic ANSD. To date, over 110 mutations have been identified in the OTOF gene according to the Human Gene Mutation Database (HGMD). Here, next-generation sequencing (NGS) revealed that the compound heterozygous mutations c.4748G>A/c.2523+1G>T and c.5248G>C/c.5098G>C of the OTOF gene were present in two Chinese ANSD patients. Each patient had a known pathogenic mutation (c.4748G>A or c.5098G>C) and a novel mutation (c.2523+1G>T or c.5248G>C). Comparative amino acid sequence analysis across different species revealed that the residues at these novel mutation sites are evolutionarily highly conservative. This indicated that the novel mutations were possible causes of the disorder in the patients. Our findings extend the OTOF mutation spectrum and further confirm the role of the OTOF gene in ANSD. [ABSTRACT FROM AUTHOR]

Mutations in the GJB2 gene (which encodes Connexin26 (Cx26)) are the most common cause of non-syndromic deafness. Previous studies showed that an extensive knockout of the Gjb2 gene in cochlear epithelium can cause severe deafness, significant hair cell (HC) loss and failure of pillar cells (a type of supporting cell, PCs) to differentiate in mice. This study aimed to establish different mouse models with gradient reductions of cochlear Cx26 expression and to investigate the effect of different reduced levels of cochlear Cx26 expression on hearing and development of PCs. According to the reduction in the levels of cochlear Cx26, these models were named high knockdown (KD), middle KD and low KD group. In the low KD group, the mice showed normal hearing and well-developed PCs. In the high KD group, up to 90 percent of supporting cells (SCs) lost Cx26 expression. These mice exhibited severe deafness, rapid hair cell degeneration and juvenile PCs. In the middle KD group, nearly half of SCs lost Cx26 expression. However, these mice showed a moderate deafness and a late-onset hair cell loss. Moreover, nearly all the PCs in mice of this group were in a partially differentiated state. These results indicated that reduction of postnatal expression of cochlear Cx26 induces hearing loss in a dose-dependent manner. Null Cx26 in a few SCs affects the developmental status of PCs and the hair cell degeneration pattern. The abnormal developmental status of PCs may be a potential cause of Gjb2 -related hearing loss. • Reduced postnatal expression of cochlear Cx26 induces hearing loss in a dose-dependent manner. • Postnatal expression of cochlear Cx26 affects the developmental status of pillar cells in a dose-dependent manner. • Distinct sensory hair cell degeneration patterns are due to different levels of residual Cx26 expression. • Deformity of pillar cells may be a potential cause of Gjb2 -related hearing loss. [ABSTRACT FROM AUTHOR]

PTPRQ gene, encoding protein tyrosine phosphatase receptor Q, is essential for the normal maturation and function of hair bundle in the cochlea. Its mutations can cause the defects of stereocilia in hair cell, which lead to nonsyndromic sensorineural hearing loss. Using next-generation sequencing and Sanger sequencing method, we identified a novel compound heterozygous missense mutation, c.4472C>T p.T1491M (maternal allele) and c.1973T>C p.V658A (paternal allele), in PTPRQ gene. The two mutations are the first reported to be the cause of recessively inherited sensorineural hearing loss. Hearing loss levels and progression involved by PTPRQ mutations among the existing cases seem to be varied, and the relationship between genotypes and phenotypes is unclear. Our data here further prove the important role of PTPRQ in auditory function and provide more information for the further mechanism research of PTPRQ-related hearing loss. [ABSTRACT FROM AUTHOR]

Objective: The present study investigated the effect of foam thickness on postural stability in patients with unilateral vestibular hypofunction (UVH) during foam posturography. Methods: Static and foam posturography were performed in 33 patients (UVH group) and 30 healthy subjects (control group) with eyes open (EO) and closed (EC) on firm surface and on 1-5 foam pad(s). Sway velocity (SV) of center of pressure, standing time before falling (STBF) and falls reaction were recorded and analyzed. Results: (1) SVs had an increasing tendency in both groups as the foam pads were added under EO and EC conditions. (2) STBFs, only in UVH group with EC, decreased with foam thickness increasing. (3) Significant differences in SV were found between the control and UVH group with EO (except for standing on firm surface, on 1 and 2 foam pad(s)) and with EC (all surface conditions). (4) Receiver operating characteristic curve analysis showed that the SV could better reflect the difference in postural stability between the two groups while standing on the 4 foam pads with EC. Conclusion: Our study showed that diagnostic value of foam posturography in detecting postural instability might be enhanced by using foam pad of right thickness. [ABSTRACT FROM AUTHOR]

Hearing loss, including genetic hearing loss, is one of the most common forms of sensory deficits in humans with limited options of treatment. Adeno-associated virus (AAV)-mediated gene transfer has been shown to recover auditory functions effectively in mouse models of genetic deafness when delivered at neonatal stages. However, the mouse cochlea is still developing at those time points, whereas in humans, the newborn inner ears are already fully mature. For effective gene therapy to treat genetic deafness, it is necessary to determine whether AAV-mediated therapy can be equally effective in the fully mature mouse inner ear without causing damage to the inner ear. This study tested several AAV serotypes by canalostomy in adult mice. It is shown that most AAVs transduce the sensory inner hair cells efficiently, but are less efficient at transducing outer hair cells. A subset of AAVs also transduces non-sensory cochlear cell types. Neither the surgical procedure of canalostomy nor the AAV serotypes damage hair cells or impair normal hearing. The studies indicate that canalostomy can be a viable route for safe and efficient gene delivery, and they expand the repertoire of AAVs to target diverse cell types in the adult inner ear. [ABSTRACT FROM AUTHOR]

Conclusion: Our study showed that sensory organization test (SOT) could principally reflect utricular function, and our cut-score of VEST ratio (the indicator of inputs from the vestibular system in balance performance) in SOT could help to screen patients with unilateral peripheral vestibular dysfunction in non-fallers. Objectives: We aimed to know SOT reflects the function of which vestibular end organs and to assess the possibility of screening patients with peripheral vestibular dysfunction in non-fall population by means of SOT. Methods: A total of 75 patients with unilateral peripheral vestibular dysfunction underwent SOT, ocular vestibular-evoked myogenic potential (oVEMP), cervical vestibular-evoked myogenic potential (cVEMP) and caloric tests. Results: Regression model indicated that oVEMP, as an independent variable, exerted the greatest influence on VEST ratio, followed by age and cVEMP. There were no significant differences in VEST ratio among groups with different extents of peripheral vestibular involvement (p>.05). VEST ratio in the vestibular impairment groups was significantly lower than in the control group and significantly higher than in fall group (p<.01). VEST ratio in group with normal oVEMP was significantly higher than in group with abnormal oVEMP (p=.013). The cut-score between populations with functional and dysfunctional vestibule was 0.649. [ABSTRACT FROM AUTHOR]

Background/aims: According to recent studies, central auditory impairments are closely related to neurodegenerative diseases. However, the mechanism of central presbycusis remains unclear. Ubiquitin C-terminal hydrolase L1 (UCHL1) is important in maintaining proteasomal activity; however, the detailed mechanism has not yet been fully elucidated. This study aims to investigate the molecular alterations involved in UCHL1 regulation during auditory cortex aging.Methods: D-Galactose (D-gal) induces oxidative stress and senescence in the auditory cortex, as reported in our previous studies. Primary auditory cortex cells were treated with D-gal for 72 h or 5 days. The proteins related to the ubiquitin proteasome system (UPS) and proteasomal activities were evaluated. UCHL1 was overexpressed, and the effects of UCHL1 on the UPS and proteasomal activity were analyzed.Results: Proteasomal activity was elevated at 72 h and decreased at 5 days in D-gal-treated primary auditory cortex cells. We also found that overexpression of UCHL1 increased the UPS-related proteins UBE1, PSMA7, ubiquitinated proteins, and monoubiquitin, and proteasomal activity.Conclusion: The results suggest that UCHL1 may modify the aging process in the auditory cortex by regulating UPS- related proteins. [ABSTRACT FROM AUTHOR]

Conclusion:Intra-tympanic dexamethasone injection (ITD) could serve as a first-line intra-tympanic (IT) treatment for Meniere’s disease (MD), regardless of hearing level. Even if the response to initial ITD course was unsatisfactory, a repeated course may be beneficial with some patients. Objectives:This study examined the effect of repeated courses of ITD administered on demand and investigated the possibility of ITD as an initial IT treatment for medically intractable MD patients. Method:Fifty-one patients who had been diagnosed with definite MD and given course(s) of ITD treatment were included. Vertigo control, pure tone average and functional disability scores were evaluated against the American Academy of Otolaryngology-Head and Neck Surgery guidelines for MD. Results:Vertigo disappeared or was substantially controlled in 58.8% and 23.5% of the patients, respectively, after the first ITD course. A repeated course further raised the complete vertigo control rate by 15.7% and intra-tympanic gentamycin injection could be postponed or avoided in 78.6% of the patients who required repeated IT treatment. Hearing was unchanged after the first course of ITD (p > .05). No significant differences were detected in the clinical profiles or laboratory findings between patients receiving single course of ITD and those on multiple courses (p > .05). [ABSTRACT FROM PUBLISHER]

The mangiferin-berberine (MB) salt was synthesized by ionic bonding of mangiferin (M) and berberine (B) at an equal molecular ratio. This study aimed to investigate the activities of MB salt in modulating lipid and glucose metabolisms in HepG2 cells. After 24 h treatment of the studying compounds, cellular AMP-activated protein kinase α (AMPKα)/acetyl-CoA carboxylase (ACC) protein levels and carnitine palmitoyltransferase (CPT) 1 activities, intracellular lipid contents, mRNA expression levels of target genes, glucose consumption, and glucose production amounts were determined. Compound C (CC) was used in the blocking experiments. Our results showed that MB salt increased p-AMPKα (Thr172)/p-ACC (Ser79) levels and CPT1 activity and suppressed oleic acid- (OA-) induced lipid accumulation and upregulation of lipogenic genes potently in HepG2 cells. The above activities of MB salt were AMPK dependent and were superior to those of M or B when administered at an equal molar concentration. MB salt enhanced basal and insulin-stimulated glucose consumption and suppressed gluconeogenesis more potently than M or B alone. The inhibiting activity of MB salt on cellular gluconeogenesis was AMPK dependent. Our results may support MB salt as a new kind of agent for the development of novel lipid or glucose-lowering drugs in the future. [ABSTRACT FROM AUTHOR]

Age-associated degeneration in the central auditory system, which is defined as central presbycusis, can impair sound localization and speech perception. Research has shown that oxidative stress plays a central role in the pathological process of central presbycusis. Thioredoxin 2 (Trx2), one member of thioredoxin family, plays a key role in regulating the homeostasis of cellular reactive oxygen species and anti-apoptosis. The purpose of this study was to explore the association between Trx2 and the phenotype of central presbycusis using a mimetic aging animal model induced by long-term exposure to d-galactose ( d-Gal). We also explored changes in thioredoxin-interacting protein ( TXNIP), apoptosis signal regulating kinase 1 ( ASK1) and phosphorylated ASK1 (p- ASK1) expression, as well as the Trx2- TXNIP/Trx2- ASK1 binding complex in the auditory cortex of mimetic aging rats. Our results demonstrate that, compared with control groups, the levels of Trx2 and Trx2- ASK1 binding complex were significantly reduced, whereas TXNIP, ASK1 p- ASK1 expression, and Trx2- TXNIP binding complex were significantly increased in the auditory cortex of the mimetic aging groups. Our results indicated that changes in Trx2 and the TXNIP-Trx2- ASK1 signal pathway may participate in the pathogenesis of central presbycusis. [ABSTRACT FROM AUTHOR]

Abstract: The time course of aminoglycoside neurotoxic effect on cochlear nucleus is still obscure. We examined dynamic pathological changes of dorsal cochlear nucleus (DCN) and investigated whether apoptosis or autophagy was upregulated in the neurotoxic course of kanamycin on DCN after kanamycin treatment. Rats were treated with kanamycin sulfate/kg/day at a dose of 500mg by subcutaneous injection for 10 days. Dynamic pathological changes, neuron density and neuron apoptosis of the DCN were examined at 1, 7, 14, 28, 56, 70 and 140 days after kanamycin treatment. The expressions of JNK1, DAPK2, Bcl-2, p-Bcl-2, Caspase-3, LC3B and Beclin-1 were also detected. Under transmission electron microscopy, the mitochondrial swelling and focal vacuoles as well as endoplasmic reticulum dilation were progressively aggravated from 1 day to 14 days, and gradually recovered from 28 days to 140 days. Meanwhile, both autophagosomes and autolysosomes were increased from 1 day to 56 days. Only few neurons were positive to the TUNEL staining. Moreover, neither the expressions of caspase-3 and DAPK2 nor neurons density of DCN changed significantly. LC3-II was drastically increased at 7 days. Beclin-1 was upgraded at 1 and 7 days. P-Bcl-2 increased at 1, 7, 14 and 28 days. JNK1 increased at 7 days, and Bcl-2 was downgraded at 140 days. LC3-B positive neurons were increased at 1, 7 and 14 days. These data demonstrated that the neurons damage of the DCN caused by kanamycin was reversible and autophagy was upregulated in the neurotoxic course of kanamycin on DCN through JNK1-mediated phosphorylation of Bcl-2 pathway. [Copyright &y& Elsevier]

Abstract: Aging is a natural process usually defined as a progressive loss of function with an accumulation of senescent cells. The clinical manifestations of this process include age-related hearing loss (AHL)/presbycusis. Several investigations indicated the association between a mitochondrial common deletion (CD) (mtDNA 4977-bp deletion in humans, corresponding to 4834-bp deletion in rats) and presbycusis. Previous researches have shown that peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) is a key regulator of mitochondrial biogenesis and energy metabolism. However, the expression of PGC-1α in the inner ear and the possible effect of PGC-1α on presbycusis are not clear. Our data demonstrated the distribution of PGC-1α and its downstream transcription factors nuclear respiratory factor-1 (NRF-1), mitochondrial transcription factor A (Tfam) and nuclear factor κB (NF-κB) in marginal cells (MCs) for the first time. To explore the role of PGC-1α in cellular senescence, we established a model of marginal cell senescence harboring the mtDNA4834 common deletion induced by d-galactose. We also found that PGC-1α and its downstream transcription factors compensatorily increased in our cell senescence model. Furthermore, the overexpression of PGC-1α induced by transfection largely increased the expression levels of NRF-1 and TFAM and significantly decreased the expression level of NF-κB in the cell senescence model. And the levels of CD, senescent cells and apoptotic cells in the cell model decreased after PGC-1α overexpression. These results suggested that PGC-1α might protect MCs in this cell model from senescence through a nuclear-mitochondrial interaction and against apoptosis. Our study may shed light on the pathogenesis of presbycusis and provide a new therapeutic target for presbycusis. [Copyright &y& Elsevier]

Abstract: There are two types of hair cells in the sensory epithelium of vestibular end organ. Type II vestibular hair cell (VHC II) is innervated by the efferent nerve endings, which employ a cholinergic inhibition mediated by SK channels through the activation of α9-containing nAChR. Our previous studies demonstrated that a BK-type cholinergic inhibition was present in guinea pig VHCs II, which may be mediated by an unknown mAChR. In this study, BK channel activities triggered by ACh were studied to determine the mAChR subtype and function. We found the BK channel was insensitive to α9-containing nAChR antagonists and m1, m3, m4 muscarinic antagonists, but potently inhibited by the m2 muscarinic antagonist. Muscarinic agonists could mimic the effect of ACh and be blocked by m2 antagonist. cAMP analog activated the BK current and adenyl cyclase (AC) inhibitor inhibited the ACh response. Inhibitor of Giα subunit failed to affect the BK current, but inhibitor of Giα and Giβγ subunits showed a potent inhibition to these currents. Our findings provide the physiological evidence that mAChRs may locate in guinea pig VHCs II, and m2 mAChRs may play a dominant role in BK-type cholinergic inhibition. The activation of m2 mAChRs may stimulate Giβγ-mediated excitation of AC/cAMP activities and lead to the phosphorylation of Ca2+ channels, resulting in the influx of Ca2+ and opening of the BK channel. [Copyright &y& Elsevier]

Oxidative damage to mtDNA is associated with excessive reactive oxygen species production. The mitochondrial common deletion (mtDNA 4977-bp and 4834-bp deletion in humans and rats, respectively) is the most typical and frequent form of mtDNA damage associated with aging and degenerative diseases. The accumulation of the mitochondrial common deletion has been proposed to play a crucial role in age-related hearing loss (presbycusis). However, the mechanisms underlying the formation and accumulation of mtDNA deletions are still obscure. In the present study, a rat mimetic aging model induced by d-Gal was used to explore the origin of deletion mutations and how mtDNA repair systems modulate this process in the inner ear during aging. We found that the mitochondrial common deletion was greatly increased and mitochondrial base excision repair capacity was significantly reduced in the inner ear in d-Gal-treated rats as compared with controls. The overexpression of mitochondrial transcription factor A induced by d-Gal significantly stimulated mtDNA replication, resulting in an increase in mtDNA copy number. In addition, an age-related loss of auditory sensory cells in the inner ear was observed in d-Gal-treated rats. Taken together, our data suggest that mitochondrial base excision repair capacity deficiency and an increase in mtDNA replication resulting from mitochondrial transcription factor A overexpression may contribute to the accumulation of mtDNA deletions in the inner ear during aging. This study also provides new insights into the development of presbycusis. [ABSTRACT FROM AUTHOR]

Abstract: Mitochondrial DNA (mtDNA) mutations, especially deletions, have been suggested to play an important role in aging and degenerative diseases. In particular, the common deletion in humans and rats (4977bp and 4834bp deletion, respectively) has been shown to accumulate with age in post-mitotic tissues with high energetic demands. Among numerous deletions, the common deletion has been proposed to serve as a molecular marker for aging and play a critical role in presbyacusis. However, so far no previous publication has quantified the contribution of common deletion to the total burden of mtDNA deletions in tissues during aging process. In the present study, we established a rat model with various degrees of aging in inner ear induced by three different doses of d-galactose (d-gal) administration. Firstly, multiple mtDNA deletions in inner ear were detected by nested PCR and long range PCR. In addition to the common deletion, three novel mtDNA deletions were identified. All four deletions, located in the major arc of mtDNA, are flanked by direct repeats and involve the cytochrome c oxidase (COX) subunit III gene, encoded by mtDNA. Additionally, absolute quantitative real-time PCR assay was used to detect the level of common deletion and total deletion burden of mtDNA. The quantitative data show that the common deletion is the most frequent type of mtDNA deletions, exceeding 67.86% of the total deletion burden. Finally, increased mtDNA copy number, reduced COX activity and mosaic ultrastructural impairments in inner ear were identified in d-gal-induced aging rats. The increase of mtDNA replication may contribute to the accelerated accumulation of mtDNA deletions, which may result in impairment of mitochondrial function in inner ear. Taken together, these findings suggest that the common deletion may serve as an ideal molecular marker to assess the mtDNA damage in inner ear during aging. [Copyright &y& Elsevier]

Background: Berberine (BBR) is a drug with multiple effects on cellular energy metabolism. The present study explored answers to the question of which CYP450 (Cytochrome P450) isoenzymes execute the phase-I transformation for BBR, and what are the bioactivities of its metabolites on energy pathways.Methods: BBR metabolites were detected using LC-MS/MS. Computer-assistant docking technology as well as bioassays with recombinant CYP450s were employed to identify CYP450 isoenzymes responsible for BBR phase-I transformation. Bioactivities of BBR metabolites in liver cells were examined with real time RT-PCR and kinase phosphorylation assay.Results: In rat experiments, 4 major metabolites of BBR, berberrubine (M1), thalifendine (M2), demethyleneberberine (M3) and jatrorrhizine (M4) were identified in rat's livers using LC-MS/MS (liquid chromatography-tandem mass spectrometry). In the cell-free transformation reactions, M2 and M3 were detectable after incubating BBR with rCYP450s or human liver microsomes; however, M1 and M4 were below detective level. CYP2D6 and CYP1A2 played a major role in transforming BBR into M2; CYP2D6, CYP1A2 and CYP3A4 were for M3 production. The hepatocyte culture showed that BBR was active in enhancing the expression of insulin receptor (InsR) and low-density-lipoprotein receptor (LDLR) mRNA, as well as in activating AMP-activated protein kinase (AMPK). BBR's metabolites, M1-M4, remained to be active in up-regulating InsR expression with a potency reduced by 50-70%; LDLR mRNA was increased only by M1 or M2 (but not M3 and M4) with an activity level 35% or 26% of that of BBR, respectively. Similarly, AMPK-α phosphorylation was enhanced by M1 and M2 only, with a degree less than that of BBR.Conclusions: Four major BBR metabolites (M1-M4) were identified after phase-I transformation in rat liver. Cell-free reactions showed that CYP2D6, CYP1A2 and CYP3A4 seemed to be the dominant CYP450 isoenzymes transforming BBR into its metabolites M2 and M3. BBR's metabolites remained to be active on BBR's targets (InsR, LDLR, and AMPK) but with reduced potency. [ABSTRACT FROM AUTHOR]

Abstract: In order to enhance oral bioavailability of berberine (BBR) for its cholesterol-lowering efficacy in vivo, a series of ester or ether prodrugs of berberrubine (M1), which is an active metabolite of BBR after first-pass metabolism, were designed, semi-synthesized, and evaluated. Among these M1 prodrugs, compound 5g possessing palmitate at the 9-position showed a moderate Log P value and esterase hydrolysis rate for releasing M1 in blood. Its cholesterol-lowering efficacy in vivo was evaluated in hyperlipidemic SD rats. Compound 5g (100mg/kg/d) reduced blood CHO and LDL-c by 35.8% and 45.5%, respectively, similar to that by BBR. It also exhibited a good safety in rats with no side-effect on liver and kidney function. Therefore, the design of M1 prodrug appears to be an effective strategy to improve pharmacokinetic feature of BBR for its lipid-lowering efficacy in vivo. [ABSTRACT FROM AUTHOR]

Abstract: One of the most common complaints among aging individuals is difficulty in understanding speech in a compromised listening environment, such as when background noise is present. Age-related hearing loss (presbycusis) is associated with both peripheral and central neural processing deficits, as it occurs even in those with only a mild peripheral hearing impairment. The current study was designed to investigate potential causative mechanisms of this impairment by using a rat model in which presbycusis is inducible by administration of d-galactose (d-gal). One group of these rats was injected subcutaneously with 150mg d-gal daily for 8weeks, while control animals received vehicle only. These groups were compared to naturally aged rats (24months) that had received no other treatment. Central auditory function of the three groups was evaluated by measuring the auditory brainstem response (ABR) and middle latency response (MLR). A TaqMan real time PCR assay was used to quantify a 4834-bp deletion in the mitochondrial DNA (mtDNA) of the auditory cortex (AC), inferior colliculus (IC) and cochlear nucleus (CN). We assessed changes in lipid peroxidation levels and apoptosis rates, and examined pathological changes corresponding to d-gal-induced aging and natural aging. Both groups of aged rats exhibited delayed ABR latencies (III, IV, V), MLR Pa latency, and I-IV interpeak latency. Moreover, increased mtDNA 4834bp deletion rates, lipid peroxidation levels, rates of neuronal apoptosis and neurodegenerative changes in the AC, IC and CN were similar among the d-gal induced and NA rats. However, the threshold of ABR in the d-gal group showed no significant change from the control group. These observations suggest that age-related central auditory dysfunction and its corresponding pathological changes are present in both naturally aging rats and the d-gal mimetic aging model. Oxidative stress, large-scale mtDNA 4834bp deletion, and apoptosis are likely to be involved in the progressive weakening of the central auditory system associated with the aging process. [Copyright &y& Elsevier]

Abstract: Berberine (BBR) is a natural compound with up-regulating activity on both low-density-lipoprotein receptor (LDLR) and insulin receptor (InsR). This one-drug-multiple-target characteristic might be suitable for the treatment of metabolic syndrome. In searching for up-regulators effective for both LDLR and InsR expression, the structure–activity relationship (SAR) analysis for BBR analogues was done. Fourteen BBR analogues were designed, synthesized and biologically evaluated. SAR analysis revealed that appropriate modifications on the phenyl ring A or D of BBR might retain the up-regulatory activities on the expression of both LDLR and InsR. Among these compounds, compound 13a bearing 9-methoxy and 10-hydroxyl on the ring D showed promising activities on either LDLR or InsR gene expression. The 10-hydroxyl of 13a could be an arm to connect proper chemical groups for optimizing drug-bioavailability in vivo. Thus, 13a could be considered to be a parent compound to make pro-drugs for either blood lipids or glucose. [Copyright &y& Elsevier]

Compound 8a exhibited the promising activity against anti-SARS-CoV-2 via inhibiting host Cat B activity, and had the advantage of broad-spectrum anti-coronavirus and anti-cytokine activity in the treatment of COVID-19. [Display omitted] • 54 aloperine derivatives were evaluated for the anti-SARS-CoV-2 activities. • Compound 8a exhibited the most promising activity against authentic SARS-CoV-2. • Compound 8a showed broad-spectrum anti-coronavirus and anti-cytokine effects. • Compound 8a displayed a good PK and safety profile in vivo. • Compound 8a blocked viral entry at a late stage by inhibiting host Cat B activity. So far, there is still no specific drug against COVID-19. Taking compound 1 with anti-EBOV activity as the lead, fifty-four 12 N -substituted aloperine derivatives were synthesized and evaluated for the anti-SARS-CoV-2 activities using pseudotyped virus model. Among them, 8a exhibited the most potential effects against both pseudotyped and authentic SARS-CoV-2, as well as SARS-CoV and MERS-CoV, indicating a broad-spectrum anti-coronavirus profile. The mechanism study disclosed that 8a might block a late stage of viral entry, mainly via inhibiting host cathepsin B activity rather than directly targeting cathepsin B protein. Also, 8a could significantly reduce the release of multiple inflammatory cytokines in a time- and dose-dependent manner, such as IL-6, IL-1β, IL-8 and MCP-1, the major contributors to cytokine storm. Therefore, 8a is a promising agent with the advantages of broad-spectrum anti-coronavirus and anti-cytokine effects, thus worthy of further investigation. [ABSTRACT FROM AUTHOR]

Forty−three tricyclic matrinic derivatives with a unique scaffold were prepared and evaluated for their stimulation effects on glucose consumption in HepG2 cells. The structure−activity relationship was systematically elucidated for the first time. Among them, compound 17a exhibited the most promising potency, and dose-dependently increased glucose consumption in L6 myotubes. It significantly lowered blood glucose, glucosylated haemoglobin and AGE level, and improved glucose tolerance and insulin resistance in KK-Ay mice as well. More importantly, 17a effectively ameliorated diabetic nephropathy (DN), as indicated by the improvement of renal function and pathological changes, and decrease of urinary protein. Furthermore, 17a could induce glycolysis but suppressed aerobic oxidation of glucose, in a similar mechanism to Metform. Our results indicated that in addition to hyperglycemia, 17a may be developed to treat diabetic complication such as DN. 17a exhibited the promising activity on glucose consumption, and may be developed to treat hyperglycemia as well as diabetic nephropathy complication. Image 1 • 43 tricyclic matrinic analogues were tested for hypoglycemic activity in vitro. • 17a exhibited the most promising activity on glucose consumption. • 17a lowered blood glucose, improved glucose tolerance and insulin resistance. • 17a ameliorated DN and pancreatic islet damage in KK-Ay mice. • Its mechanism was to induce glycolysis but suppressed aerobic oxidation of glucose. [ABSTRACT FROM AUTHOR]

Abstract: Berberine (BBR, 1) is a novel cholesterol-lowering agent that up-regulates low-density-lipoprotein receptor (LDLR) expression through a mechanism different from that of statins. Because of the unique mode of action and good safety record, BBR provoked our interest to do structure modification at different domains for its cholesterol-lowering activity. Nineteen BBR analogues with substituents on the benzene ring D were synthesized in the present study. The analysis of structure–activity relationship (SAR) indicated that the two methoxyl groups in an ortho-distribution on this benzene ring afforded a good activity. Among the 19 analogues, compound 8j bearing a methoxyl at both 10- and 11-position showed an increased LDLR up-regulatory activity in respect to BBR, and therefore has been selected as a promising cholesterol-lowering drug candidate for further evaluation. [Copyright &y& Elsevier]

This study is designed to investigate the effects of berberine (BBR) on galectin-3 (Gal-3) and the relationships to its suppressive activities on adipocyte differentiation, proliferation and adiposity. Our results showed that BBR greatly suppressed the differentiation and proliferation of mouse primary preadipocytes isolated from epididymal white adipose tissue (eWAT), during which the expression level of Gal-3 was down-regulated significantly. Overexpression of Gal-3 totally abolished the suppressive activities of BBR on Gal-3 expression, preadipocyte differentiation and proliferation. BBR reduced Gal-3 promoter activity, destabilized its mRNA and inhibited firefly luciferase activity of a recombinant plasmid containing the Gal-3 3′ untranslated region (UTR). Furthermore, BBR up-regulated microRNA (miRNA) let-7d expression and the suppressive activity on Gal-3 3′UTR was abolished by point mutation on the let-7d binding site. In mice fed a high-fat diet (HFD), BBR up-regulated let-7d and down-regulated Gal-3 expression in eWAT; it also suppressed adipocyte differentiation and proliferation and reduced adiposity greatly. In summary, our study proves that BBR inhibits the differentiation and proliferation of adipocytes through down-regulating Gal-3, which is closely associated with its anti-obesity effect. Our results may support the future clinical application of BBR for the treatment of obesity or related diseases. [ABSTRACT FROM AUTHOR]

Background: With the increasing popularity of mobile phones, the potential hazards of radiofrequency electromagnetic radiation (RF-EMR) on the auditory system remain unclear. Apart from RF-EMR, humans are also exposed to various physical and chemical factors. We established a lipopolysaccharide (LPS)-induced inflammation in vitro model to investigate whether the possible sensitivity of spiral ganglion neurons to damage caused by mobile phone electromagnetic radiation (at specific absorption rates: 2, 4 W/kg) will increase. Methods: Spiral ganglion neurons (SGN) were obtained from neonatal (1- to 3-day-old) Sprague Dawley® (SD) rats. After the SGN were treated with different concentrations (0, 20, 40, 50, 100, 200, and 400 μg/ml) of LPS, the Cell Counting Kit-8 (CCK-8) and alkaline comet assay were used to quantify cellular activity and DNA damage, respectively. The SGN were treated with the moderate LPS concentrations before RF-EMR exposure. After 24 h intermittent exposure at an absorption rate of 2 and 4 W/kg, DNA damage was examined by alkaline comet assay, ultrastructure changes were detected by transmission electron microscopy, and expression of the autophagy markers LC3-II and Beclin1 were examined by immunofluorescence and confocal laser scanning microscopy. Reactive oxygen species (ROS) production was quantified by the dichlorofluorescin-diacetate assay. Results: LPS (100 μg/ml) induced DNA damage and suppressed cellular activity (P < 0.05). LPS (40 μg/ml) did not exhibit cellular activity changes or DNA damage (P > 0.05); therefore, 40 μg/ml was used to pretreat the concentration before exposure to RF-EMR. RF-EMR could not directly induce DNA damage. However, the 4 W/kg combined with LPS (40 μg/ml) group showed mitochondria vacuoles, karyopyknosis, presence of lysosomes and autophagosome, and increasing expression of LC3-II and Beclin1. The ROS values significantly increased in the 4 W/kg exposure, 4 W/kg combined with LPS (40 μg/ml) exposure, and H2O2 groups (P < 0.05, 0.01). Conclusions: Short-term exposure to radiofrequency electromagnetic radiation could not directly induce DNA damage in normal spiral ganglion neurons, but it could cause the changes of cellular ultrastructure at special SAR 4.0 W/kg when cells are in fragile or micro-damaged condition. It seems that the sensitivity of SGN to damage caused by mobile phone electromagnetic radiation will increase in a lipopolysaccharide-induced inflammation in vitro model. [ABSTRACT FROM AUTHOR]