Licochalcone A induces cell cycle arrest in human lung squamous carcinoma cells via the PI3K/Akt signaling pathway / 南方医科大学学报

OBJECTIVE@#To investigate the effect of licochalcone A (LCA) on the proliferation and cell cycle of human lung squamous carcinoma cells and explore its possible molecular mechanism.@*METHODS@#MTT assay was used to detect the changes in proliferation of H226 cells after treatment with different concentrations of LCA for 48 h, and the IC50 of LCA was calculated. Flow cytometry was used to analyze cell cycle changes in H226 cells treated with 10, 20, and 40 μmol/L LCA, and the expressions of cyclin D1, cyclin-dependent kinase CDK2 and CDK4, and p-PI3K, PI3K, p-Akt, and Akt in the treated cells were detected using Western blotting. The effect of intraperitoneal injection of LCA for 24 days on tumor volume and weight was assessed in a BALB/c-nu mouse model bearing lung squamous carcinoma xenografts.@*RESULTS@#MTT assay showed that LCA significantly decreased the viability of H226 cells with an IC50 of 28.3 μmol/L at 48 h. Flow cytometry suggested that LCA treatment induced obvious cell cycle arrest at the G1 phase. LCA treatment also significantly decreased the expressions of cyclin D1, CDK2, and CDK4, and inhibited the phosphorylation of PI3K and Akt in H226 cells. In the tumor-bearing mice, LCA treatment for 24 days significantly reduced the tumor volume and weight.@*CONCLUSION@#LCA is capable of inhibiting the proliferation and inducing cell cycle arrest in lung squamous carcinoma cells possibility by regulating the PI3K/Akt singling pathway.

Wnt2 overexpression protects PINK1B9 transgenic flies by improving mitochondrial function / 医学研究生学报

Objective PINK1 and Parkin are directly invoveled in the regulation and maintenance of mitochondrial functional morphology. We aim to explore the effect of Wnt2 overexpression on PINK1B9 Mutant Drosophila and its mechanism in this study. Methods The GAL4-UAS system was used to construct the normal control flies（W1118/ + ；MHC-GAL4/+）, PINK1B9 transgenic Drosophila model flies（UAS-PINK1B9 /y；MHC-GAL4 / +；Parkinson's disease model of Drosophila melanogaster), the Wnt2 overexpression flies（UAS-PINK1B9 /y；MHC-GAL4 / Wnt2 OE） and the Wnt2 RNAi flies（UAS-PINK1B9 /y；MHC-GAL4 /Wnt2）. On the 5th day, the abnormal wings phenotype rate and flying rate of flies were observed. The contents of Ndufs3 proteins were detected by Western blot. The mRNA expression levels of PGC-1α, Nrf1 and TFAM related to mitochondrial metabolism and synthesis were detected by real-time fluorescence quantitative PCR. The morphology of mitochondria was observed by electron microscopy. Complex I and Complex II function was detected by high-resolution mitochondrial respiratory system. Results Compared with the normal control flies, PINK1B9 transgenic Drosophila model flies showed increased abnormal wings phenotype rate([1.87±0.06]% vs [68.79±0.70]%), decreased flying rate([ 97.51±0.52)% vs(3.95±0.53)%], and the differences were statistically significant(P<0.05); Compared with PINK1B9 transgenic Drosophila model flies, the Wnt2 RNAi flies showed decreased abnormal wings phenotype rate[(10.14±1.72)%], increased flying rate([41.83±2.57]%)(P<0.05). Compared with the normal control flies, PINK1B9 transgenic Drosophila model flies showed decreased expression levels of PGC-1α and Nrf1,Ndufs3 proteins, Complex I and Complex II(P<0.05);On the contrary, the Wnt2 RNAi flies showed increased trends compared with PINK1B9 transgenic Drosophila model flies(P<0.05). Conclusion Overexpression of Wnt2 protects PINK1B9 transgenic Drosophila models, which is related to the improvement of mitochondrial function.

Feasibility of transplanting human bone marrow mesenchymal stem cells into manganese poisoning rats / 中国组织工程研究

BACKGROUND: Studies have shown that bone marrow mesenchymal stem cells (BMSCs) can treat central nervous system diseases. BMSCs have the function of self-renewal and differentiation into a variety of neural cell types. BMSCs with self-renewal and multi-directional differentiation abilities can successfully differentiate into dopaminergic neurons after transplantation into an animal model. OBJECTIVE: To observe the effect of transplanted BMSCs on behavior and dopaminergic neurons in rats with manganese poisoning. METHODS: Rat models of manganese poisoning were constructed by intraperitoneal injection of MnCl2?4H2O into Sprague-Dawley rats. The model rats were then randomly divided into two groups, BMSCs and phosphate buffered solution (PBS) control group, and 5 μL of passage 3 human BMSCs suspension or equivalent PBS was transplanted into the right striatum of the manganese poisoning rats. One month after transplantation, the rats were subjected to behavioral assessment. The differentiation of BMSCs was observed by immunofluorescence. The contents of dopamine, brain-derived neurotrophic factor, glial cell-derived neurotrophic factor in the right striatum of rats were detected by ELISA. RESULTS AND CONCLUSION: The behavioral score of the BMSCs treated group was significantly lower than that of the PBS control group after transplantation (P < 0.05). Double-labeled positive cells for human-specific nuclear antigen/tyrosine hydroxylase (hNUC/TH) and human-specific nuclear antigen/glial cell-derived acidic protein (hNUC/GFAP) were observed in the BMSCs treated group after transplantation. Meanwhile, hNUC/TH and hNUC/GFAP double-labeled positive cells were undetected in the PBS control group after transplantation. The expression levels of dopamine, brain-derived neurotrophic factor, glial cell-derived neurotrophic factor in the BMSCs treated group were higher than those in the PBS control group. This suggests that BMSCs can improve the behavior of manganese poisoning rats and can differentiate into dopaminergic neurons and astrocytes.

Relationship between simulated weightlessness-induced muscle spindle change and muscle atrophy / 生理学报

One of the most important and urgent issues in the field of space medicine is to reveal the potential mechanism underlying the disused muscle atrophy during the weightlessness or microgravity environment. It will conduce to find out effective methods for the prevention and treatment of muscle atrophy during a long-term space flight. Increasing data show that muscle spindle discharges are significantly altered following the hindlimb unloading, suggesting a vital role in the progress of muscle atrophy. In the last decades, we have made a series of studies on changes in the morphological structure and function of muscle spindle following simulated weightlessness. This review will discuss our main results and related researches for understanding of muscle spindle activities during microgravity environment, which may provide a theoretic basis for effective prevention and treatment of muscle atrophy induced by weightlessness.

Relationship between mRNA expression of MnSOD and manganese neurotoxicity / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between mRNA expression of manganese superoxide dismutase (MnSOD) and manganese neurotoxicity.</p><p><b>METHODS</b>Thirty-one patients with occupational chronic manganese poisoning (case group), as well as 31 controls exposed to the same condition (control group), were included in the study. Whole blood RNA was extracted, and the mRNA expression of MnSOD was measured by RT-PCR; the two groups were compared in terms of the mRNA expression of MnSOD. PC12 cells were treated with 0, 100, 200, 400, 600, 800, and 1000 ümol/L MnCl₂ for l, 2, 3, and 4 d; the cell viability was determined by MTT assay, and the mRNA expression of MnSOD was measured by RT-PCR.</p><p><b>RESULTS</b>The case group had significantly lower mRNA expression of MnSOD than the control group (0.390 ± 0.080 vs 0.582 ± 0.219, P < 0.05). MnCl2 had a toxic effect on PC12 cells; the concentration of MnCl₂ was positively correlated with the toxic effect but negatively correlated with the mRNA expression of MnSOD.</p><p><b>CONCLUSION</b>MnSOD mRNA may be involved in the manganese-induced damage of nerve cells. It is hypothesized that high mRNA expression of MnSOD may play an inhibitory effect on manganese neurotoxicity.</p>

Method of isolation of intrafusal fibres of muscle spindle in soleus of rats / 生理学报

Capsule restricts the further study on muscle spindle function and the involved mechanism. The aim of this study was to establish the isolation method of intrafusal fibres from the isolated rat muscle spindle. Intrafusal fibres were harvested from muscle spindle of soleus muscle in rats using neutrase-collagenase digestion. A variety of incubation mediums have been tested to find out an appropriate medium of intrafusal fibers in vitro. Trypan blue staining was used to detect cell death, and patch clamp was used to record resting potential. The results showed that the intrafusal fibres incubated with amine acid-saline solution were almost all dead. DMEM could maintain good condition of the fibres, but excess CO2 ventilation would induce cellular swelling or even death. While Leiboviz's 15 (L-15) medium can guarantee 1-2 h of physiological condition of the intrafusal fibres. Coverslips treated with gelatin, polylysine and serum was the better interfaces for the intrafusal fibres to adhere easily, compared with regularly treated coverslip. The resting potential of intrafusal fibres was (-45.3 ± 5.1) mV, consistent with others obtained from in vivo muscle spindle from cats and frogs. These results suggest that the isolation method of the intrafusal fibres has been successfully established in the present study, providing a new approach in better understanding of muscle spindle activities and the involved mechanism.

Electrophysiological characteristics of the isolated muscle spindle in rats / 生理学报

The aim of this study was to observe the electrophysiological characteristics of the isolated rat muscle spindle. The muscle spindle was isolated from rat soleus and the afferent discharge of the isolated muscle spindle was recorded by air-gap technique. In the basic physiological salt solution, the spontaneous impulses of muscle spindle were at a lower level with irregular intervals. The mean frequency of afferents was (51.78 ± 25.63) impulses/1 000 s (n = 13). The muscle spindle afferents were significantly increased and maintained over time by the addition of certain amino acids during the observation. The number of the action potential recorded per 1 000 s was 200-1 000 [mean: (687.62 ± 312.56) impulses/1 000 s, n = 17]. In addition to the typical propagated action potential, a large number of abortive spikes were observed. The results indicate that the activities of isolated muscle spindles in rats can be well maintained by the addition of certain amino acids. The results initially establish and provide the possibility for further research conducted in isolated rat muscle spindles.

Decreased neurotrophin-3 expression of intrafusal muscle fibers in rat soleus muscles under simulated weightlessness / 生理学报

The present study aimed to study the changes of neurotrophin-3 (NT-3) expression of intrafusal muscle fibers in rat soleus muscles under simulated weightlessness. The tail-suspension (SUS) rat model was used to simulate weightlessness. Forty mature female Sprague-Dawley rats were randomly assigned to ambulatory control (CON), 3-day SUS, 7-day SUS, 14-day SUS and 21-day SUS groups. Immunohistochemistry ABC staining method and enzyme linked immunosorbent assay (ELISA) were used to detect the NT-3 expression of intrafusal muscle fibers in rat soleus muscles. The results from the immunohistochemistry staining technique showed that the extrafusal muscle fibers did not exhibit the NT-3-like immunoreactivity, and NT-3-like immunoreactivity was mainly expressed in nuclear bag 1 and nuclear bag 2 fibers of the muscle spindles. The ELISA results showed that the expression quantity of NT-3 in rat soleus muscles in control, 3-day SUS, 7-day SUS, 14-day SUS and 21-day SUS groups were (14.23±1.65), (14.11±1.53), (13.09±1.47), (12.45±1.51) and (9.85±1.52) pg/mg of tissue respectively. Compared to the control group, the expression quantity of NT-3 was significantly decreased after 14 days of SUS (P<0.05). After 21 days of SUS, the NT-3 expression was further reduced (P<0.01). These results suggest that simulated weightlessness induces an obvious decrease in the NT-3 expression level of intrafusal fibers in rat soleus muscles. Accompanying the simulated weightlessness extension, NT-3 expression in rat soleus muscle spindles is progressively decreased. These changes may contribute to the proprioceptive adaptations to microgravity.

Effects of 100 Hz sinusoidal vibration on H reflex and M wave in rat soleus muscle following immobilization / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of 100 Hz sinusoidal vibration on H reflex and M wave in rat soleus muscle following immobilization.</p><p><b>METHODS</b>The immobilization of rat soleus muscle was induced as a disuse muscle model, and 100 Hz sinusoidal vibration was generated by a vibrator and applied to the immobilized soleus muscle, then the changes of H reflex and M wave in muscle were observed after 14 d.</p><p><b>RESULTS</b>Compared to control, after 14 d of immobilization M(max) in soleus muscle decreased (P<0.01), stimulus threshold and S(max) increased (P<0.01); Hmax and H(max)/M(max) decreased (P<0.05, S(max) increased (P<0.05). Compared to immobilized soleus muscle, after 14 d of immobilization with 100 Hz sinusoidal vibration, the M(max) increased(P<0.01), stimulus threshold and S(Mmax) decreased (P<0.05), H(max) (P<0.01) increased and H(max)/M(max) increased (P<0.05).</p><p><b>CONCLUSION</b>100 Hz sinusoidal vibration plays a significant antagonist role against the changes in H reflex and M wave in rat soleus muscle following immobilization.</p>

Epimedium alleviates chemotherapy-induced damage to the ultrastructure and function of rat epididymides / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the protective action of Epimedium against chemotherapy-induced damage to rat epididymides.</p><p><b>METHODS</b>Fifty 60-day-old male rats were divided into a control, a model and a treatment group. Procarbazine was injected into the abdominal cavity of the model rats at the dose of 30 mg/(kg x d). In addition to procarbazine, Epimedium was given intragastrically to the treatment group. The changes in the ultrastructure of the epididymis were observed after 10 and 20 days.</p><p><b>RESULTS</b>Electron microscopy showed that the chemotherapy-induced damages to the epididymal epithelia mainly included cell swelling, local cavitation of mitochondria, tumor-like change in nucleoli, agglutination of marginal translocation of heterochromatin and cell apoptosis. The damage to the epithelial ultrastructure was slight in the treatment group as compared with the model rats. Chemotherapy significantly affected sperm concentration, sperm viability and sialic acid (SA), which were (15.59 +/- 4.01) x 10(6)/ml, (76.71 +/- 10.11)% and (19.38 +/- 9.34) g/mg prot in the model group in comparison with (10.63 +/- 3.82) x 10(6)/ml (P < 0.01), (60.03 +/- 7.54)% (P < 0.01) and (13.62 +/- 7.81) g/g prot (P < 0.05) in the control. Epimedium significantly increased sperm viability in the treatment group (60.03 +/- 7.54)% as compared with the model rats (69.90 +/- 12.58)% (P < 0.05).</p><p><b>CONCLUSION</b>Epimedium can lessen chemotherapy-induced damage to the epididymis and protect the reproductive function of rats.</p>

Effects of prenatal stress on kinetic properties of high-voltage-activated Ca2+ channel in freshly isolated offspring rat hippocampal CA3 pyramidal neurons / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of prenatal stress (PNS) on kinetic properties of high-voltage-activated (HVA) Ca(2+) channel in freshly isolated offspring rat hippocampal CA3 pyramidal neurons.</p><p><b>METHODS</b>The pregnant rats were exposed to restraint stress, and the hippocampal CA3 pyramidal neurons were freshly isolated from the offspring rats to record voltage-gate Ca(2+) channel currents in these neurons using whole-cell configuration of patch-clamp technique.</p><p><b>RESULTS</b>PNS significantly increased HVA calcium current density and integral current but did not alter the steady-state activation and steady-state inactivation properties of HVA Ca(2+) channel in the offspring rat CA3 neurons. The maximal HVA calcium current density was -40.89-/+0.31 pA/pF in the control group (n=10) and -49.44-/+0.37 pA/pF in PNS group (n=8, P<0.01). The maximal integral current of the HVA Ca(2+) channel was 106.81-/+4.20 nA*ms in the control group (n=10) and 133.49-/+2.59 nA*ms in the PNS group (n=8, P<0.01).</p><p><b>CONCLUSION</b>Maternal exposure to stress during the critical phase of pregnancy may result in long-lasting effects on the ion channels of the hippocampal neurons in the offspring rats.</p>

Randomized clinical study of surgery versus radiotherapy alone in the treatment of resectable esophageal cancer in the chest / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To compare the treatment results between radical surgery and late course accelerated hyperfractionated radiotherapy (LCAHFR) for patients with resectable esophageal cancer in the chest.</p><p><b>METHODS</b>From June 1998 to September 2002, 269 patients with resectable esophageal cancer in the chest were randomized into two groups: 135 in surgery group and 134 in radiotherapy. The surgery group received esophagectomy including resection of the lesion and 5 cm margin at both ends from the lesion as well as surrounding lymph nodes > or = 5 mm and fatty tissue. In the radiotherapy group: irradiation field for the lesion in the upper esophageal cancer included the gross lesion, bilateral supraclavicular nodes and 4 cm of normal esophagus from lower margin of the gross disease; for the esophageal cancer at the middle segment, it included the gross disease with 4 cm normal esophagus from both ends of the lesion; for the lesion in the lower esophageal cancer, it included 4 cm of normal esophagus and the gross lesion as well as the draining gastric lymph nodes. The width of the irradiation field was 5-6 cm. The 90% isodose volume was covered by the entire CTV with 3-5 beams, in a conventionally fractionated RT at 1.8-2.0 Gy/d for the first two thirds of treatment course to a dose of about 50-50.4 Gy followed by LCAHFR using reduced fields (2 cm extended margin at both ends of the lesion) , twice daily at 1.5 Gy per fraction ( with aminimal interval of 6 h between fractions) to a dose of 18-21 Gy. The total dose whole radiotherapy was 68.4-71.0 Gy.</p><p><b>RESULTS</b>The 1-, 3- and 5-year overall survival rate was 93.3%, 61.5% and 36.9% in the surgery group versus 88.6%, 56.2% and 34.7% in the radiotherapy group without statistical difference between the two groups. The 1-, 3- and 5-year progression free survival rate was 75.9%, 43.7% and 23.1% in the surgery group and 73.3%, 39.7% and 20.6%, respectively, in the radiotherapy group without statistical difference between the two groups either.</p><p><b>CONCLUSION</b>The results treated by late course accelerated hyperfractionated conformal radiotherapy alone may be comparable to that by radical surgery for patient with resectable esophageal cancer in the chest.</p>