[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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).
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.
Journal of Neuroinflammation 05/2015; 12(1):105. DOI:10.1186/s12974-015-0300-1 · 5.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The NLR pyrin domain containing 3 (NLRP3) inflammasome plays a crucial role in lung disease and may have a similar role in upper respiratory tract inflammation. We therefore constructed a C57BL/6 mouse model of acute rhinosinusitis induced by Staphylococcus aureus and investigated the role of the NLRP3 inflammasome in this model. Mice were classified as non-inoculated group (group A) and inoculated groups (groups B, C, D and E, sacrificed 1, 3, 7 and 14 days after inoculation, respectively). Hematoxylin-eosin staining showed that each group had inflammatory cell infiltration, except group A. The damage of the nasal mucosa was aggravated gradually over time. Western blot and immunofluorescence showed that the structural proteins of the NLRP3 inflammasome (NLRP3, ASC (apoptosis-associated speck-like protein containing CARD), procaspase-1) in groups B, C, D and E were increased gradually. But they were reduced in group B compared with group A, except for NLRP3. Western blot showed that the cleavage fragment of procaspase-1, p20 in groups B, C, D and E was increased gradually. Real-time PCR showed that the corresponding mRNAs of the structural proteins were changed the same as their proteins. IL-1β mRNA and mature IL-1β protein were increased gradually in groups A, B, C, D and E. These results indicate that NLRP3 inflammasome activation was associated with the acute rhinosinusitis, and that there was a positive correlation between the expression level of the NLRP3 inflammasome and the severity of acute rhinosinusitis.
International Journal of Molecular Sciences 09/2014; 15(9):15806-15820. DOI:10.3390/ijms150915806 · 2.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recent studies indicated that interleukin (IL)-17, growth-related oncogene (GRO)-α and IL-8 play an important role in the pathogenesis of nasal polyps. However, the effects of the increased amount of IL-17 and the production of GRO-α and IL-8 in human nasal polyp fibroblasts are not completely understood. This study aimed to determine the effects of the increased IL-17 on the changes of GRO-α and IL-8 expression in human nasal polyp fibroblasts and further investigate the mechanism of neutrophil infiltration in nasal polyps. Nasal polyp fibroblasts were isolated from six cases of human nasal polyps, and the cells were stimulated with five different concentrations of IL-17. Real-time fluorescence quantitative polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of GRO-α and IL-8. The mRNA of GRO-α and IL-8 was expressed in unstimulated controls and remarkably increased by stimulation with IL-17. Moreover, the levels of GRO-α and IL-8 produced by fibroblasts were increased gradually with the increases in IL-17 concentrations. The present study showed that nasal fibroblasts can produce GRO-α and IL-8, and their production is remarkably enhanced by IL-17 stimulation, thereby clarifying the mechanism of the IL-17 mediated neutrophil infiltration in nasal polyps. These findings might provide a rationale for using IL-17 inhibitors as a treatment for nasal inflammatory diseases such as nasal polyps.
Journal of Huazhong University of Science and Technology 08/2014; 34(4):591-5. DOI:10.1007/s11596-014-1321-1 · 0.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Type II vestibular hair cells (VHCs II) contain big-conductance Ca2+-dependent K+ channels (BK) and L-type calcium channels. Our previous studies in guinea pig VHCs II indicated that acetylcholine (ACh) evoked the BK current by triggering the influx of Ca2+ ions through l-type Ca2+ channels, which was mediated by M2 muscarinic ACh receptor (mAChRs). Aminoglycoside antibiotics, such as gentamicin (GM), are known to have vestibulotoxicity, including damaging effects on the efferent nerve endings on VHCs II. This study used the whole-cell patch clamp technique to determine whether GM affects the vestibular efferent system at postsynaptic M2-mAChRs or the membrane ion channels. We found that GM could block the ACh-induced BK current and that inhibition was reversible, voltage-independent, and dose-dependent with an IC50 value of 36.3 ± 7.8 µM. Increasing the ACh concentration had little influence on GM blocking effect, but increasing the extracellular Ca2+ concentration ([Ca2+]o) could antagonize it. Moreover, 50 µM GM potently blocked Ca2+ currents activated by (-)-Bay-K8644, but did not block BK currents induced by NS1619. These observations indicate that GM most likely blocks the M2 mAChR-mediated response by competing with Ca2+ at the l-type calcium channel. These results provide insights into the vestibulotoxicity of aminoglycoside antibiotics on mammalian VHCs II.
International Journal of Molecular Sciences 04/2014; 15(4):6757-71. DOI:10.3390/ijms15046757 · 2.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To study the effect of neonatal immunization with different dosage allergen on the immunity of mice when grown.
Fifty neonatal BALB/c mice were divided into 4 groups randomly and subcutaneous injected with different dosage of ovalbumin (OVA) on day 1, 8 and 15 after born [NS group(10): injected with saline alone; NS + AL group (10): injected with saline and AL(OH)3; small dosage (SD) group (15): injected with 10 microg OVA and AL(OH)3; large dosage (LD) group (15): injected with 1000 microg OVA and AL(OH)3]. The mice were then challenged using caudal vein injection on 5 weeks old (NS group and NS + AL group were challenged with saline, SD group and LD group were challenged with 100 microg OVA). The blood was collected 1 week later to examine OVA specific IgE, IgG1 and IgG2a. Mononuclear cells were drawn from the spleen and cultured. Concentration of IL-4, IFN-r, IL-10 was examined in the cultural supernatant. Flow cytometry was used to test the expression of CD4+ IL-4+, CD4+ IFN-gamma+, CD4 IL-10 cells.
It was found that concentration of OVA specific IgE (OVA-sIgE) in SD group (0.33 +/- 0.18) was significantly higher than that of NS (0.07 +/- 0.01) and NS + AL (0.09 +/- 0.04) group (t value was -3.46 and -3.21, all P < 0.01), and LD group (0.17 +/- 0.10) as well (t = 2.58, P < 0.05). The concentration of OVA-sIgE was higher in LD group than that of NS group (t = -2.53, P < 0.05), but similar with that of NS + AL group (t = -2.04, P > 0.05). Both the concentration of OVA-sIgG1 and sIgG2a was higher in SD and LD group than that of NS and NS + AL group (all P < 0.05). The concentration of IL-4, IFN-gamma and IL-10 in the cultural supernatant of spleen mononuclear was all higher in SD group than that of NS and NS + AL group (all P < 0.01). The ratio of IFN-gamma/IL-4 was significantly lower in SD group than that of NS and NS + AL group (t value was 2.14, 3.44, all P < 0.05), while the same ratio was higher in LD group than that of NS and NS + AL group (t value was -2.14, -1.61, all P < 0.05). Ratio of CD4+ IL-4+ cells was significant lower in LD group than that of SD group (P < 0.05), while it was not different with that of NS and NS + AL group (P > 0. 05).
Neonatal immunization with low dosage OVA could generate a specific immunity with Th2 direction, while with large dosage OVA could generate a specific immunity with Th1 direction.
Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery 07/2013; 48(7):563-7.
[Show abstract][Hide abstract] ABSTRACT: Acetylcholine (ACh) is the principal vestibular efferent neurotransmitter among mammalians. Pharmacologic studies prove that ACh activates a small conductance Ca2+-activated K+ channels (KCa) current (SK2), mediated by α9-containing nicotinic ACh receptor (α9nAChR) in mammalian type II vestibular hair cells (VHCs II). However, our studies demonstrate that the m2 muscarinic ACh receptor (m2mAChR) mediates a big conductance KCa current (BK) in VHCs II. To better elucidate the correlation between these two distinct channels in VHCs II of guinea pig, this study was designed to verify whether these two channels and their corresponding AChR subtypes co-exist in the same VHCs II by whole-cell patch clamp recordings. We found that m2mAChR sensitive BK currents were activated in VHCs II isolated by collagenase IA, while α9nAChR sensitive SK2 currents were activated in VHCs II isolated by trypsin. Interestingly, after exposing the patched cells isolated by trypsin to collagenase IA for 3 min, the α9nAChR sensitive SK2 current was abolished, while m2mAChR-sensitive BK current was activated. Therefore, our findings provide evidence that the two distinct channels and their corresponding AChR subtypes may co-exist in the same VHCs II, and the alternative presence of these two ACh receptors-sensitive currents depended on isolating preparation with different enzymes.
International Journal of Molecular Sciences 05/2013; 14(5):8818-31. DOI:10.3390/ijms14058818 · 2.86 Impact Factor
[Show abstract][Hide abstract] 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 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 expression 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.
Brain research 01/2013; 1502. DOI:10.1016/j.brainres.2012.12.049 · 2.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aging has been associated with mitochondrial DNA damage. P66Shc is an age-related adaptor protein that has a substantial impact on mitochondrial metabolism through regulation of the cellular response to oxidative stress. Our study aimed to establish a D-galactose (D-gal)-induced inner ear aging mouse model and to investigate the potential role of p66Shc and its serine 36-phosphorylated form in the inner ear during aging by using this model. Real-time PCR was performed to detect the mtDNA 3873-bp deletion and the level of p66Shc mRNA in the cochlear lateral wall. Western blot analysis was performed to analyze the total and mitochondrial protein levels of p66Shc and the level of Ser36-P-p66Shc in the cochlear lateral wall. Immunofluoresence was performed to detect the location of the Ser36-P-p66Shc expression in the cochlear lateral wall. The results showed that the accumulation of the mtDNA 3873-bp deletion, total and mitochondrial protein levels of p66Shc and level of Ser36-P-p66Shc were significantly increased in the cochlear lateral wall of the D-gal-treated group when compared to the control group and that Ser36-P-p66Shc was mainly localized in the cytoplasm of the cells in the stria vascularis. During aging, the oxidative stress-related increase of p66Shc and Ser36-P-p66Shc might be associated with the accumulation of the mtDNA 3873-bp deletion in the inner ear.
PLoS ONE 11/2012; 7(11):e50483. DOI:10.1371/journal.pone.0050483 · 3.23 Impact Factor
[Show abstract][Hide abstract] 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 Ca(2+) channels, resulting in the influx of Ca(2+) and opening of the BK channel.
Hearing research 02/2012; 285(1-2):13-9. DOI:10.1016/j.heares.2012.02.003 · 2.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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.
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.
[Show abstract][Hide abstract] 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.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 07/2011; 712(1-2):11-9. DOI:10.1016/j.mrfmmm.2011.03.013 · 3.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
[Show abstract][Hide abstract] ABSTRACT: 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.
The purpose of this study was to develop a more suitable rat model that demonstrated closer resemblance to the pathophysiological process in AIED.
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.
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.
[Show abstract][Hide abstract] ABSTRACT: Aging has been associated with mitochondrial DNA (mtDNA) common deletion (CD). Age changes in the central auditory system are well known to affect speech perception. Base excision repair (BER) is the major type of DNA repair in mitochondria. The current study was designed to investigate potential causative mechanisms of central presbycusis by using a rat mimetic aging model induced by subcutaneous administration of D-galactose (D-gal). Quantitative real-time PCR and Western blotting analyses were performed to identify the mtDNA 4834 bp deletion and selected mitochondrial DNA repair enzymes, DNA polymerase γ (pol γ) and 8-oxoguanine DNA glycosylase (OGG1). Cell apoptosis in the auditory cortex was detected using terminal deoxynucleotidyltransferase mediated UTP nick-end labeling (TUNEL). Our data showed that mtDNA 4834 bp deletion and TUNEL-positive cells were significantly increased and the expression of pol γ and OGG1 were remarkably down-regulated in the auditory cortex in D-gal-treated rats compared to control rats. During aging, increased mtDNA damage likely results from decreased DNA repair capacity in the auditory cortex. DNA repair enzymes such as pol γ and OGG1 may provide novel pharmacological targets to promote DNA repair and rescue the central auditory system in patients with degenerative diseases.
[Show abstract][Hide abstract] 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 150 mg D-gal daily for 8 weeks, while control animals received vehicle only. These groups were compared to naturally aged rats (24 months) 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 4834 bp 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 4834 bp deletion, and apoptosis are likely to be involved in the progressive weakening of the central auditory system associated with the aging process.
Brain research 07/2010; 1344:43-53. DOI:10.1016/j.brainres.2010.04.082 · 2.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To investigate the effects of trans-cinnamaldehyde (TCA) on the human leukemia K562 cell line and the cytotoxicity of cytokine-induced killer (CIK) cells against K562 cells.
Apoptosis, Fas expression, and mitochondrial transmembrane potential in K652 cells were analyzed using flow cytometry. K562 cells were labeled with CFSE. The cytotoxic effect of expanded CIK cells on CFSE-labeled K562 cells was determined by FACS flow cytometry.
Treatment with TCA 180 micromol/L for 9 h induced apoptosis in 8.9%+/-1.23% of K562 cells. Treatment with 120 or 180 micromol/L TCA for 24 h significantly increased the apoptotic cells to 18.63%+/-1.42 % and 38.98%+/-2.74%, respectively. TCA significantly upregulates Fas expression and decreases mitochondrial transmembrane potential in K562 cells. TCA treatment at 120 and 180 micromol/L for 9 h enhanced the percentage of lysis of K562 cells by expanded CIK cells from 34.84%+/-2.13% to 48.21%+/-2.22 % and 64.81%+/-3.22% at the E:F ratio of 25:1 and from 49.26%+/-3.22% to 57.81%+/-5.13% and 73.36%+/-5.98% at E:F ratio of 50:1.
TCA exerts cytotoxic effects on human leukemia K562 cells by inducing apoptosis and synergizing the cytotoxicity of CIK cells against K562 cells. These properties of TCA are beneficial to the treatment of leukemia, even in the patients who have received hematopoietic stem cells transplantation (HSCT).
[Show abstract][Hide abstract] ABSTRACT: determine the feasibility of manganese superoxide dismutase (MnSOD) gene therapy for protecting the cochlear function against aminoglycoside-induced oxidative stress in aging rats.
The aging model of SD rats were obtained with 8 weeks daily of D-gal (150 mg/kg per day) hypodermic injection. In the 9th week, amikacin (500 mg/kg per day) were injected intramuscularly into some aging SD rats. The viral particles of recombinant adeno-associated viral vector II/MnSOD (6 microl, 5 x 10(11) vector genomes/ml) were injected into the perilymph through the round window membrane (RWM). The feasibility of MnSOD gene therapy against aminoglycoside-induced oxidative stress in aging rats was evaluated with the methods of caspase-3 protein analysis, apoptosis detection with immunohistochemical, the detection of MnSOD concentration, stretched preparation of basilar membrane and evaluation of hearing threshold with ABR-click.
Compared with the control group, the concentration of MnSOD of cochlear tissue was increased (P < 0.05), and the active fragment expression of caspase-3, the numbers of apoptosis bodies and the hearing threshold were decreased (P < 0.05).
MnSOD could play a partly role to treat cochlear aminoglycoside-induced oxidative damage in aging rats.
Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery 08/2009; 44(8):657-63.
[Show abstract][Hide abstract] ABSTRACT: To determine which of the two, recombinant adeno-associated viral vector 2 (rAAV2) and recombinant adenovirus vector 5 (rAd5), is more suitable for gene transfer in rodent cochlea.
The rAAV2-EGFP and rAd5-EGFP particles were injected into the perilymph through round window membrane. The target tissue accessibility, time course of expression, tissue toxicity of gene transfer and effects on hearing were evaluated.
The expression of EGFP was detected in spiral ligament, strial vascukarises, Reissner membrane, basilar membrane, spiral ganglion, and contralateral cochlea. EGFP expression in the rAAV2 lasted over 60 days, with peak expression between days 14 and 60. EGFP in the rAd5 was detected within 24 h of transfection, and peak expression was observed between days 1 to 21. EGFP activity decreased sharply on day 30 after transfection with rAd5, while high EGFP expression was observed 60 days after transfection with rAAV2.
AAV has significant advantages for long-term transgene expression and no ototoxicity in the cochlea compared to adenovirus vectors.
Zhonghua yi xue za zhi 06/2009; 89(19):1351-5. DOI:10.3760/cma.j.issn.0376-2491.2009.19.016