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Atorvastatin, a lipid-lowering medication, provides neuroprotective effects, although the precise mechanisms of action remain unclear. Our previous studies confirmed activated autophagy following spinal cord injury, which was conducive to recovery of neurological functions. We hypothesized that atorvastatin could also activate autophagy after spinal cord injury, and subsequently improve recovery of neurological functions. A rat model of spinal cord injury was established based on the Allen method. Atorvastatin (5 mg/kg) was intraperitoneally injected at 1 and 2 days after spinal cord injury. At 7 days post-injury, western blot assay, reverse transcription-polymerase chain reaction, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining results showed increased Beclin-1 and light chain 3B gene and protein expressions in the spinal cord injury + atorvastatin group. Additionally, caspase-9 and caspase-3 expression was decreased, and the number of TUNEL-positive cells was reduced. Compared with the spinal cord injury + saline group, Basso, Beattie, and Bresnahan locomotor rating scale scores significantly increased in the spinal cord injury + atorvastatin group at 14-42 days post-injury. These findings suggest that atorvastatin activated autophagy after spinal cord injury, inhibited apoptosis, and promoted recovery of neurological function.

To investigate the effects of salvia miltiorrhiza injection (SM) on gentamicin (GM)-induced expression of nitric oxide synthase (NOS) isoforms in guinea pig cochlea, and to explore the protective mechanism of SM on GM-induced ototoxicity.40 guinea pigs were randomly assigned to 4 groups: control group, GM group, SM group and GM plus SM group. Expression of NOS isoforms in the guinea pig cochlea was detected by the SABC method of immunohistochemistry and microscope image analysis technique. Auditory threshold was tested by auditory brainstem response (ABR) measurement.Inducible NOS (iNOS/NOS II) expression and ABR threshold in GM plus SM group were both significantly declined as compared with those in GM group (P0.01). Moreover, change of iNOS expression was in high correlation with that of ABR threshold ([r]0.7, P0.01). While expression of neuronal NOS (nNOS/NOS I) and endothelial NOS (eNOS / NOS III) showed no significant differences in all groups.SM had no effect on the expression of nNOS and eNOS, but could inhibit iNOS high-expression induced by GM to reduce excessive generation of NO, therefore SM could protect against GM ototoxicity.

Hearing loss or ototoxicity is one of the major side effects associated with the use of the antibiotics, particularly aminoglycosides (AGs), which are the most commonly used antibiotics worldwide. However, the molecular and cellular events involved in the antibiotic-induced ototoxicity remains unclear. In the present study, we test the possibility that prestin, the motor protein specifically expressed in the basolateral membrane of outer hair cells (OHCs) in the cochlea with electromotility responsible for sound amplification, may be involved in the process of AG-induced apoptosis in OHCs. Our results from both mice model and cultured cell line indicate a previously unexpected role of prestin, in mediating antibiotic-induced apoptosis, the effect of which is associated with its anion-transporting capacity. The observed downregulation of prestin mRNA prior to detectable apoptosis in OHCs and hearing loss in the antibiotic-treated mice is interesting, which may serve as a protective mechanism against hearing loss induced by AGs in the early stage.

To investigate the effects of injectio Salvia Miltiorrhiza (SM) on gentamicin (GM)-induced free radical formation in guinea pig cochlea, and to explore possible mechanisms on GM-induced ototoxicity.Biochemical assays of superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in guinea pig cochlea, combined with auditory brainstem response (ABR) measurement and transmission electron microscopic observation were used in this investigation.SOD activity was significantly declined while MDA content was distinctly increased in cochlear tissues after GM injection (P0.01). Moreover, they were well correlated with auditory function damage (|r|0.7). Co-treatment with SM evidently enhanced SOD activity and decreased MDA content (P0.01, P0.05). Furthermore, auditory function was markedly ameliorated. Morphological changes of cochlea were consistent with those of hearing function.Lipid peroxidation elicited by free radical was involved in GM-induced cochleotoxicity. SM might enhance SOD activity and prevent lipid peroxidation. As the result it might alleviate GM ototoxicity, and improve auditory function.

To establish a mice model of cisplatin-induced ototoxicity, and to investigate the effect of cisplatin on apoptosis of spiral ganglion cell and expression of caspase-3 in mouse cochlea.Terminal deoxynucleotidyl transferase-mediated nick end labeling method (TUNEL) was used to monitor the apoptosis of spiral ganglion cell. Envision method of immunohistochemistry was applied to detect the expression of caspase-3 in cochlea. Auditory brainstem response (ABR) was measured to observe the change of hearing.The weight and hearing of mice in different dose of cisplatin groups were declined significantly as compared with those of control group (P0.05, P0.01), and the TUNEL positive cell number and expression of caspase-3 were greater remarkably with the more cisplatin injected.A mouse model of cisplatin-induced ototoxicity can be established. Cisplatin can lead to the apoptosis of spiral ganglion cells, and caspase-3 has participated in this apoptosis process, which approves further that apoptosis might be one of the mechanisms of cisplatin ototoxicity.

Antioxidant therapy protects against aminoglycoside-induced ototoxicity in animal models. A clinically suitable antioxidant must not affect the therapeutic efficacy of aminoglycosides or exhibit any side effects of its own. In addition, the treatment should be inexpensive and convenient in order to be implemented in developing countries where the use of aminoglycosides is most common. Standardized Salviae miltiorrhizae extracts (Danshen) are used clinically in China and contain diterpene quinones and phenolic acids with antioxidant properties. We combined in vitro and in vivo approaches to investigate the effect of a clinically approved injectable Danshen solution on aminoglycoside-induced free radical generation and ototoxicity. In vitro, Danshen inhibited gentamicin-dependent lipid peroxidation (formation of conjugated dienes from arachidonic acid), as well as the gentamicin-catalyzed formation of superoxide (in a lucigenin-based chemiluminescence assay) and hydroxyl radicals (oxidation of N,N-dimethyl- p -nitrosoaniline). Danshen extracts were then administered to adult CBA mice receiving concurrent treatment with kanamycin (700 mg/kg of body weight twice daily for 15 days). Auditory threshold shifts induced by kanamycin (approximately 50 dB) were significantly attenuated. Danshen did not reduce the levels in serum or antibacterial efficacy of kanamycin. These results suggest that herbal medications may be a significantly underexplored source of antidotes for aminoglycoside ototoxicity. Such traditional medicines are widely used in many developing countries and could become an easily accepted and inexpensive protective therapy.

Mammalian cells in vivo frequently express primary cilia. Although some fully differentiated cell types rarely, if ever, express them, most do, indicating that they are regular cell organelles. Their expression can also be explored in vitro, where conditions--physical and chemical, intrinsic and extrinsic--permit experimental approaches which give far greater control than in vivo. This 'state of the art' paper covers briefly the general biology of primary cilia, highlights the current situation with regard to our understanding of their relevance and importance in cell biology from various facets of our recent research, much of it in collaboration with other laboratories world-wide, and outline future work aimed at answering some basic and applied questions about them, within a context of an increasing awareness that signalling between cells is of the utmost importance in understanding proliferation control and its value in cancer research, the major remit of this unit.