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ObjectiveTo investigate the expression of glial cell line-derived neurotrophic factor （GDNF） and androgen receptor （AR） in testicular peritubular cells （TPCs） of cryptorchidism mouse models and explore the theoretical significance of cryptorchidism-induced spermatogenesis dysfunction. MethodsA total of 30 five-week-old male ICR rats were divided randomly by using random number table method into 6 groups. Cryptorchidism was surgically induced in 3 randomly selected groups and the other 3 groups underwent sham surgery as the control groups. On days 4， 7 and 14 after surgery， we harvested the mice testes of the 3 groups and their corresponding control groups， then measured the testicular volumes， analyzed the testicular histopathology and detected the mRNA and protein expression levels of AR and GDNF in TPCs by immunofluorescence， real-time PCR and Western blot. ResultsIn normal control groups， on days 4， 7 and 14 after surgery， the testicular volumes were （125.58±19.22） mm3，（123.45±20.12） mm3， （140.09±13.62） mm3 ， respectively. Clear layers of spermatogenic cells were well arranged and abundant sperm cells were found. Peritubular cells were morphologically homogeneous， with slim-spindle appearance and normal cell thickness. The mRNA expression levels of AR were 1.00±0.05， 1.06±0.07 and 1.19±0.13； GDNF mRNA 1.00±0.04， 1.09±0.05， and 1.10±0.07. The protein expression levels of AR were 1.01±0.01， 0.79±0.02 and 1.01±0.04； GDNF protein （18.68±0.43） pg/mL， （14.39±0.36） pg/mL and （16.88±0.37） pg/mL. In cryptorchidism groups， on days 4， 7 and 14 after surgery， the testicular volumes were （115.64±3.91） mm3， （69.51±14.97） mm3 and （44.86±5.56） mm3， respectively. Spermatogenic cells were disorganized， seminiferous tubules were disrupted， peritubular cells shrank， bent and fractured. The mRNA expression levels of AR were 0.76±0.06， 0.53±0.04， and 0.29±0.02； GDNF mRNA 0.72±0.05， 0.42±0.02 and 0.30±0.03. The protein expression levels of AR were 0.54±0.02， 0.98±0.04 and 0.31±0.01； GDNF protein （8.50±0.34） pg/mL， （17.44±0.32） pg/mL and （6.83±0.34） pg/mL. Statistically significant differences （P < 0.05） were found in 7-day and 14-day testicular volumes between control and cryptorchidism groups but not in the 4-day testicular volume （P > 0.05）. Testicular volumes， AR and GDNF mRNA and protein expression in control groups had no statistically significant difference （P > 0.05）， while those in cryptorchidism groups showed a trend of gradual decline in the amount and the differences between groups were statistically significant （P < 0.05）. ConclusionsIn surgery-induced cryptorchidism mice， after the induction， the expression of AR and GDNF in TPCs showed a gradual decrease over time. AR and GDNF play a major role in mediating the TPCs damage in cryptorchidism. This study provides a theoretical basis for mechanism researches of cryptorchidism-induced spermatogenesis dysfunction.
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@#Objective To investigate the effect of traumatic brain injury on the expressions of glial cell line-derived neurotrophic factor (GDNF) and its receptors in brain stem of rats.Methods 55 male Sprague-Dawley rats were divided into the normal control group, sham surgery group and injury groups. The rats of injury groups were subjected to Marmarou's closed traumatic brain injury and then were subdivided into 1 h, 2 h, 4 h, 8 h, 12 h, 24 h, 48 h, 72 h and 5 d groups according to the time elapsed after injury. The expressions of GDNF and its receptors (GFRα-1 and Ret) were tested with immunohistochemistry.Results Mild expressions of GDNF and its receptors were observed in brain stem of rats in the normal control group and sham surgery group. The number of GDNF positive neurons reached the peak level at 2 h in brain stem after injury, and that of GFRα-1 and Ret positive neurons reached the peak level at 4 h after injury.Conclusion The expressions of GDNF and its receptors increase significantly at the early time in brain stem of rats after injury. The similar temporal patterns of expressions of GDNF and its receptors are observed in brain stem after brain injury.
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@#Objective To investigate the expressions of glial cell line-derived neurotrophic factor(GDNF)and its receptors,GFRα-1 and Ret,in cortex of rats after closed traumatic cerebral injury.Methods Male Sprague-Dawley rats were divided into normal control,sham and injury groups.The rats of injury groups were subjected to Marmarou's closed traumatic cerebral injury and then were subdivided into 1 h,2 h,4 h,8 h,12 h,24 h,48 h,72 h and 5 d groups according to the time elapsed after injury.The expression of GDNF and its receptors were determined with immunohistochemistry.Results Mild expression of GDNF and its receptors were observed in cortex of rats in control groups.The number of GDNF positive neurons reached the peak level in cortex 2 h after injury,and that of GFRα-1 and Ret positive neurons reached the peak level 4 h after injury.Conclusion The expressions of GDNF and its receptors increased significantly at the early time in cortex of rats after injury,as well as its receptors.It suggests that GDNF and its receptors play an important role after traumatic cerebral injury.
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This study was aimed at to investigating the protective effect of a combined treatment with glial cell line derived neurotrophic factor (GDNF) and neurotrophin 3 (NT 3) on noise induced outer hair cell (OHC) damage. Guinea pigs were subjected to receiving infusion of an artificial perilymph containing GDNF (100ng/ml) and NT 3 (2 5?g/ml) into one cochlea via a mini osmotic pump. Three days later, the animals were exposed to a 4kHz narrow band noise at 115 dB SPL for 4h. The control animals received the same treatment except GDNF and NT 3. Thresholds of auditory brainstem responses (ABRs), elicited by clicks, were measured before and 3 days after the surgery of the pump implantation, and 10 days following noise exposure. Then, the subjects were sacrificed and the cochleas were stained with Hoechst 33342. The specimens were examined under a fluorescence microscope for quantitative assessment of the OHC nuclear morphology. The results showed that compared with the control animals, the drug treated ones had significant less swollen OHC nuclei ( P
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Objective To study effects of GDNF and HSV GDNF on apoptosis of spinal cord motoneurons after scratch injury in vitro. Methods In the period of culture cell,motor neurons were periodically observed and counted.Scratch injury was executed on culturing 12th day,in the same time,cultured neurons were divided into 4 groups,and each group was given corresponding medium(medium serum free control group,serum group,HSV GDNF group,GDNF group).On the 4th and 7th day after scratch injury,TUNEL staining was respectively performed,and the number and the mean densities of apoptotic motoneurons were observed. Results The number of living motoneurons was in inverse proportion to time of scratch injury in each group.The number of apoptotic motoneurons from control group,HSV GDNF group to GDNF group was successively decreased as well as the mean densities of apoptotic motoneurons on the 4th and 7th day after scratch injury.Furthermore,the effects of groups with serum were no better than those of medium serum free groups,in the same time,difference was not obviously in HSV GDNF group and GDNF group. Conclusion GDNF and HSV GDNF can decrease apoptosis of injured motoneurons in vitro .It suggests that GDNF and HSV GDNF might play an important role in the growth and development of motor neurons.