OBJECTIVETo analyze the impact of olfactory nerve transection on the apoptosis of mice olfactory receptor neurons (ORN), and discuss the reliability of this experimental model.

METHODSAfter olfactory nerve transection of mice, anterograde horseradish peroxidase (HRP) tracing was performed to confirm the completion of nerve transection. On 8 h, 2 d, 3 d and 5 d after surgery, TdT mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) was used to observe the apoptosis of ORN, while relative semi-quantitative RT-PCR and immunohistochemistry were used to reflect the expression of olfactory marker protein (OMP, special marker of mature ORN) in olfactory epithelium.

RESULTSNo HRP label was observed in olfactory bulb after olfactory nerve transaction. Both TUNEL-positive and OMP-positive cells were ORN. After the surgery, TUNEL-positive cells increased remarkably and peaked on 2 d after the surgery. Meanwhile OMP mRNA in olfactory epithelium began to decrease markedly till 5 d after the surgery, and the olfactory epithelium got thinner accordingly.

CONCLUSIONSThis experimental model can be used reliably to sever mice olfactory nerve and manipulate simultaneous apoptosis of mice ORN.

Animals ; Apoptosis ; Denervation ; Mice ; Mice, Inbred C57BL ; Olfactory Nerve ; cytology ; metabolism ; surgery ; Olfactory Receptor Neurons ; metabolism ; pathology

BACKGROUNDSmall noncoding microRNAs regulate gene expression in cardiac development and disease and have been implicated in the aging process and in the regulation of extracellular matrix proteins. However, their role in age-related cardiac remodeling and atrial fibrillation (AF) was not well understood. The present study was designed to decipher molecular mechanisms underlying age-related atrial structural remodeling and AF.

METHODSThree groups of dogs were studied: adult and aged dogs in sinus rhythm and with persistent AF induced by rapid atrial pacing. The expressions of microRNAs were measured by quantitative real-time polymerase chain reaction. Pathohistological and ultrastructural changes were tested by light and electron microscopy. Apoptosis index of myocytes was detected by TUNEL.

RESULTSSamples of atrial tissue showed the abnormal pathohistological and ultrastructural changes, the accelerated fibrosis, and apoptosis with aging and/or in AF dogs. Compared to the adult group, the expressions of microRNAs-21 and -29 were significantly increased, whereas the expressions of microRNAs-1 and -133 showed obvious downregulation tendency in the aged group. Compared to the aged group, the expressions of microRNAs-1, -21, and -29 was significantly increased in the old group in AF; contrastingly, the expressions of microRNA-133 showed obvious downregulation tendency.

CONCLUSIONThese multiple aberrantly expressed microRNAs may be responsible for modulating the transition from adaptation to pathological atrial remodeling with aging and/or in AF.

Age Factors ; Animals ; Apoptosis ; Atrial Fibrillation ; etiology ; Atrial Remodeling ; Connective Tissue Growth Factor ; physiology ; Dogs ; Electrocardiography ; Fibrosis ; In Situ Nick-End Labeling ; MicroRNAs ; analysis ; physiology ; Myocardium ; pathology ; ultrastructure

In the present study, we analyzed the role of Ginkgo biloba extract in lipopolysaccharide(LPS)-induced acute lung injury (ALI). ALI was induced in mice by intratracheal instillation of LPS. G. biloba extract (12 and 24 mg·kg(-1)) and dexamethasone (2 mg·kg(-1)), as a positive control, were given by i.p. injection. The cells in the bronchoalveolar lavage fluid (BALF) were counted. The degree of animal lung edema was evaluated by measuring the wet/dry weight ratio. The superoxidase dismutase (SOD) and myeloperoxidase (MPO) activities were assayed by SOD and MPO kits, respectively. The levels of inflammatory mediators, tumor necrosis factor-a, interleukin-1b, and interleukin-6, were assayed by enzyme-linked immunosorbent assay. Pathological changes of lung tissues were observed by H&E staining. The levels of NF-κB p65 and COX-2 expression were detected by Western blotting. Compared to the LPS group, the treatment with the G. biloba extract at 12 and 24 mg·kg(-1) markedly attenuated the inflammatory cell numbers in the BALF, decreased NF-κB p65 and COX-2 expression, and improved SOD activity, and inhibited MPO activity. The histological changes of the lungs were also significantly improved. The results indicated that G. biloba extract has a protective effect on LPS-induced acute lung injury in mice. The protective mechanism of G. biloba extract may be partly attributed to the inhibition of NF-κB p65 and COX-2 activation.
Acute Lung Injury ; chemically induced ; drug therapy ; metabolism ; Animals ; Bronchoalveolar Lavage Fluid ; cytology ; Cell Count ; Cyclooxygenase 2 ; genetics ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; drug effects ; Ginkgo biloba ; chemistry ; Interleukin-1beta ; analysis ; Interleukin-6 ; analysis ; Lipopolysaccharides ; Lung ; immunology ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Peroxidase ; metabolism ; Phytotherapy ; Plant Extracts ; pharmacology ; Pulmonary Edema ; Superoxide Dismutase ; metabolism ; Transcription Factor RelA ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; analysis