The role of propofol on mouse oocyte meiotic maturation and early embryo development.

SummaryPropofol is a intravenous anaesthetic most commonly used in ultrasound oocyte retrieval. We studied if the use of propofol had an effect on mouse oocyte maturation, pregnancy, childbirth and progeny and investigated the correlation between propofol side effects and reproductive performance in mice. There was no statistical difference in mating, pregnancy, childbirth, litter size, the number of stillbirths and survival between each group (P>0.05). Propofol also had no effect on polar body extrusion in oocyte maturation as well as on pronucleus formation and, subsequently, early embryo development (P>0.05). An increased concentration of propofol had no effect on this result, although propofol at more than 0.01 mg/ml reduced polar body extrusion. Different concentrations of propofol had no effect on oocyte culture in vitro, pronucleus formation and early embryo development.

Sodium Channel Voltage-Gated Beta 2 Plays a Vital Role in Brain Aging Associated with Synaptic Plasticity and Expression of COX5A and FGF-2.

The role of sodium channel voltage-gated beta 2 (SCN2B) in brain aging is largely unknown. The present study was therefore designed to determine the role of SCN2B in brain aging by using the senescence-accelerated mice prone 8 (SAMP8), a brain senescence-accelerated animal model, together with the SCN2B transgenic mice. The results showed that SAMP8 exhibited impaired learning and memory functions, assessed by the Morris water maze test, as early as 8 months of age. The messenger RNA (mRNA) and protein expressions of SCN2B were also upregulated in the prefrontal cortex at this age. Treatment with traditional Chinese anti-aging medicine Xueshuangtong (Panax notoginseng saponins, PNS) significantly reversed the SCN2B expressions in the prefrontal cortex, resulting in improved learning and memory. Moreover, SCN2B knockdown transgenic mice were generated and bred to determine the roles of SCN2B in brain senescence. A reduction in the SCN2B level by 60.68% resulted in improvement in the hippocampus-dependent spatial recognition memory and long-term potential (LTP) slope of field excitatory postsynaptic potential (fEPSP), followed by an upregulation of COX5A mRNA levels and downregulation of fibroblast growth factor-2 (FGF-2) mRNA expression. Together, the present findings indicated that SCN2B could play an important role in the aging-related cognitive deterioration, which is associated with the regulations of COX5A and FGF-2. These findings could provide the potential strategy of candidate target to develop antisenescence drugs for the treatment of brain aging.

[Study of apoptosis related factors regulatory mechanism of resveratrol to human skin squamous cell carcinoma A431 xenograft in nude mice].

OBJECTIVE: To explore the anti-tumor effects of resveratrol (Res) upon human skin squamous cell carcinoma A431 xenograft in nude mice and elucidate the regulatory mechanisms of survivin and caspase-3. METHODS: The model of human skin squamous cell carcinoma (A431) xenograft in nude mice was established. And the animals were randomly divided into saline-negative control, cyclophosphamide (CTX) positive control, Res high-, medium- and low-dosage and blank control groups (n = 10 each). After drug intervention, tumor-bearing mice were sacrificed. The tumor growth curve was plotted and the Res inhibition rate calculated by terminal tumor weight. The morphological changes of tumor cell among groups were observed by hematoxylin and eosin staining; cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling TUNEL; the impact of Res upon the protein expressions of survivin and caspase-3 in tumor issues was observed by Western blot. Analysis of variance and Pearson's correlation were employed for statistical analyses. RESULTS: (1) By the end of treatment, the tumor volume of CTX, Res high-, medium-, low-dosage, saline-negative control and blank control groups were (1154 ± 255), (1002 ± 115), (1207 ± 176), (1342 ± 211), (1642 ± 226), (1564 ± 156) mm(3) respectively, and tumor weight of CTX, Res high-, medium-, low-dosage, saline-negative control and blank control groups (1.84 ± 0.30), (1.72 ± 0.39), (1.96 ± 0.40), (2.67 ± 0.73), (3.16 ± 0.52), (3.33 ± 0.59) g respectively. Through analysis of variance, the tumor volume and weight of Res high-, medium-, low-dosage groups were smaller than those of saline-negative control and blank control groups (all P < 0.05). The inhibition rate of Res high-, medium- and low-dosage groups were 45.57%, 37.97% and 15.51% respectively. (2) The apoptosis index of the above groups were 36.79% ± 8.86%, 33.15% ± 6.00%, 18.09% ± 3.92%, 10.53% ± 4.20%, 3.87% ± 1.63%, 2.73% ± 1.61%. Through analysis of variance, the apoptosis index of Res groups were higher than those of saline-negative control and blank control groups (all P < 0.05). (3) The protein expression of survivin/ß-actin of each group were 0.48 ± 0.20, 0.19 ± 0.11, 0.22 ± 0.12, 0.28 ± 0.24, 0.98 ± 0.41, 0.85 ± 0.34. The protein expression of caspase-3/ß-actin of each group were 0.42 ± 0.09, 0.31 ± 0.10, 0.31 ± 0.07, 0.22 ± 0.08, 0.14 ± 0.04, 0.13 ± 0.05 respectively. Through analysis of variance, the protein expression of survivin of Res groups was lower than those of the saline-negative control and blank control groups (all P < 0.05). And the protein expression of caspase-3 of Res groups were higher than those of the saline-negative control and blank control group (all P < 0.05). Through Pearson's analysis, the protein expression of survivin and caspase-3 had no correlation (r = -0.279, P > 0.05). CONCLUSIONS: Res inhibits the growth of human skin squamous cell carcinoma A431 xenograft in nude mice. And its mechanism may be associated with the apoptosis of tumor cell through the depression of survivin and the activation of caspase-3.

Recombinant DNA vaccine against inhibition of neurite outgrowth promotes functional recovery associated with endogeous NGF expression in spinal cord hemisected adult rats.

Axonal regeneration across the site of spinal cord lesion is often aborted in adult mammalian species. The use of DNA vaccine to nullify the inhibitory molecules has been shown to be effective in promoting axonal regeneration in injured spinal cord. The possible molecular mechanisms, however, remain to be elucidated. The present study showed that the administration of recombinant DNA vaccine encoding multiple domains, Nogo-66, Nogo-N, TnR, and MAG, significantly improved hindlimb locomotor functions in rats subjected to ablation of the dorsal halves of the cord. Western blot analysis demonstrated that nerve growth factor (NGF) levels in the spinal cord of immunized rats were significantly upregulated than those of control rats. Immunohistochemistry as well as in situ hybridization confirmed that NGF was expressed in neurons of the spinal cord. These findings indicated that functional recovery in immunized rats could be correlated with endogeous NGF expression in hemisected rat spinal cords.

Roles of platelet-derived growth factor-B expression in the ventral horn and motor cortex in the spinal cord-hemisected rhesus monkey.

It is well known that platelet-derived growth factor-B (PDGF-B), a member of the neurotrophic factor family, is involved in normal physiological conditions, pathological changes, and neuroregulation following lesions. But the roles of endogenous PDGF-B in neuroregulation following spinal cord injury are far from being well known, especially in primates. This study explored the role of PDGF-B in the spinal cord and motor cortex in rhesus monkeys subjected to cord hemisection. Evaluation of the hindlimb motor function and the cortical somatosensory evoked potentials (CSEP) demonstrated a significant partial recovery from 30 days post-operation (dpo) to 90 dpo. Immunostaining revealed PDGF-B expression in neurons and scattered macrophages in the spinal cord. The number of PDGF-B immunoreactive neurons in the ventral horn of the spinal cord decreased significantly at the injury site at 14 dpo, followed by a rapid increase that surpassed the numbers in the control group at 30 dpo, and remained at these levels until 90 dpo. The protein levels of PDGF-B and platelet-derived growth factor receptor-beta (PDGFR-beta) as assessed by Western blot, as well as the mRNA levels of PDGF-B as assessed by RT-PCR demonstrated a tendency similar to that seen with immunohistochemistry. PDGF-B antibody administration effectively decreased locomotor function in the hindlimbs, especially on the injured side. No PDGF-B immunoreactive cells were detected in the motor cortex. Taken together, the present findings indicate that intrinsic PDGF-B expressed in the spinal cord may play an essential role in neuroregulation in primates following cord hemisection.