Neurogenic effect of VEGF is related to increase of astrocytes transdifferentiation into new mature neurons in rat brains after stroke.

To study the cellular mechanism of vascular endothelial growth factor (VEGF)-enhanced neurogenesis in ischemic brain injury, we used middle cerebral artery occlusion (MCAO) model to induce transient focal ischemic brain injury. The results showed that ischemic injury significantly increased glial fibrillary acidic protein immunopositive (GFAP(+)) and nestin(+) cells in ipsilateral striatum 3 days following MCAO. Most GFAP(+) cells colocalized with nestin (GFAP(+)-nestin(+)), Pax6 (GFAP(+)-Pax6(+)), or Olig2 (GFAP(+)-Olig2(+)). VEGF further increased GFAP(+)-nestin(+) and GFAP(+)-Pax6(+) cells, and decreased GFAP(+)-Olig2(+) cells. We used striatal injection of GFAP targeted enhanced green fluorescence protein (pGfa2-EGFP) vectors combined with multiple immunofluorescent staining to trace the neural fates of EGFP-expressing (GFP(+)) reactive astrocytes. The results showed that MCAO-induced striatal reactive astrocytes differentiated into neural stem cells (GFP(+)-nestin(+) cells) at 3 days after MCAO, immature (GFP(+)-Tuj-1(+) cells) at 1 week and mature neurons (GFP(+)-MAP-2(+) or GFP(+)-NeuN(+) cells) at 2 weeks. VEGF increased GFP(+)-NeuN(+) and BrdU(+)-MAP-2(+) newborn neurons after MCAO. Fluorocitrate, an astrocytic inhibitor, significantly decreased GFAP and nestin expression in ischemic brains, and also reduced VEGF-enhanced neurogenic effects. This study is the first time to report that VEGF-mediated increase of newly generated neurons is dependent on the presence of reactive astrocytes. The results also illustrate cellular mechanism of VEGF-enhanced neural repair and functional plasticity in the brains after ischemic injury. We concluded that neurogenic effect of VEGF is related to increase of striatal astrocytes transdifferentiation into new mature neurons, which should be very important for the reconstruction of neurovascular units/networks in non-neurogenic regions of the mammalian brain.

Myocardial ischemic post-conditioning attenuates ischemia reperfusion injury via PTEN/Akt signal pathway.

OBJECTIVES: To investigate whether myocardial ischemic post-conditioning attenuates ischemia reperfusion injury via PTEN/Akt signal pathway. DESIGN: Forty-five male Sprague-Dawley rats were randomly divided into three groups: Sham, Ischemia reperfusion (I/R) and Ischemic post-conditioning (IPost) group. After the experiment finished, myocardial infarction area was examined. Serum creatine phosphokinase and lactate dehydrogenase activity were detected at baseline and the end of reperfusion. The protein levels of PTEN, Akt, p-Akt, Bax and Bcl-2 were measured by Western blot method. RESULTS: Myocardial infarct size was significantly reduced in IPost as compared to I/R. Results were confirmed by serum creatine phosphokinase and lactate dehydrogenase activity. In addition, PTEN and Bax protein expression were inhibited and the p-Akt and bcl-2 protein expression were enhanced in IPost compared with I/R (P < 0.05). At the same time, the ratio of Bax and Bcl-2 was decreased in IPost (P < 0.05). However, ischemic post conditioning did not affect the total Akt level (P > 0.05). CONCLUSIONS: We confirmed that ischemic post-conditioning protects the heart against reperfusion injury. It is important that we demonstrated that the cardioprotective effect of ischemic post-conditioning was involved in the inhibition of PTEN, activation of the PI3K/Akt pathway and reduction of the cardiomyocyte apoptosis.

Striatal astrocytes transdifferentiate into functional mature neurons following ischemic brain injury.

To determine whether reactive astrocytes stimulated by brain injury can transdifferentiate into functional new neurons, we labeled these cells by injecting a glial fibrillary acidic protein (GFAP) targeted enhanced green fluorescence protein plasmid (pGfa2-eGFP plasmid) into the striatum of adult rats immediately following a transient middle cerebral artery occlusion (MCAO) and performed immunolabeling with specific neuronal markers to trace the neural fates of eGFP-expressing (GFP(+)) reactive astrocytes. The results showed that a portion of striatal GFP(+) astrocytes could transdifferentiate into immature neurons at 1 week after MCAO and mature neurons at 2 weeks as determined by double staining GFP-expressing cells with ßIII-tubulin (GFP(+)-Tuj-1(+)) and microtubule associated protein-2 (GFP(+)-MAP-2(+)), respectively. GFP(+) neurons further expressed choline acetyltransferase, glutamic acid decarboxylase, dopamine receptor D2-like family proteins, and the N-methyl-D-aspartate receptor subunit R2, indicating that astrocyte-derived neurons could develop into cholinergic or GABAergic neurons and express dopamine and glutamate receptors on their membranes. Electron microscopy analysis indicated that GFP(+) neurons could form synapses with other neurons at 13 weeks after MCAO. Electrophysiological recordings revealed that action potentials and active postsynaptic currents could be recorded in the neuron-like GFP(+) cells but not in the astrocyte-like GFP(+) cells, demonstrating that new GFP(+) neurons possessed the capacity to fire action potentials and receive synaptic inputs. These results demonstrated that striatal astrocyte-derived new neurons participate in the rebuilding of functional neural networks, a fundamental basis for brain repair after injury. These results may lead to new therapeutic strategies for enhancing brain repair after ischemic stroke.

New striatal neurons form projections to substantia nigra in adult rat brain after stroke.

Previous studies have demonstrated that newborn striatal neurons can functionally integrate with local neural networks in adult rat brain after injury. In the present study, we determined whether these newly generated striatal neurons can develop projections to the substantia nigra, a target of striatal projection neurons. We used 5'-bromodeoxyuridine (BrdU) and a retroviral vector expressing green fluorescent protein (GFP) combined with multiple immunostaining labels of newborn striatal neurons, and nigral microinjection of fluorogold (FG) to trace the striatonigral projection in adult rat brain at different weeks following a transient middle cerebral artery occlusion (MCAO). We found that FG positive (FG(+)) cells could be detected in newly generated neurons (BrdU(+)-NeuN(+) and GFP(+)-NeuN(+)) in ipsilateral striatum clearly at 12, but not 2 weeks after MCAO. The data suggest that ischemia-induced newborn striatal projection neurons could form long axons that targeted the substantia nigra (striatonigral projection pathway) and that have intact axonal transport from the nerve terminal to cell body. These new striatal neurons express glutamate NR2 and dopamine D2L receptors, which form the molecular basis for responding to the inputs from cortical glutamatergic and nigral dopaminergic projection neurons. Our data provide the first morphological evidence that newborn neurons in the striatum, a non-neurogenic region, can establish new striatonigral neural circuits, important pathways for the maintenance of motor function. These results help us to understand endogenous cellular mechanisms of brain repair, and suggest that increasing adult neurogenesis could be a practical strategy for enhancing the efficacy of rehabilitative therapy in stroke patients.

Study on canceration law of gastric mucosal dysplasia based on syndromes of Chinese medicine.

OBJECTIVE: To study the syndrome evolution law of Chinese medicine (CM) in the patients with gastric mucosal dysplasia. METHODS: Three hundred and twenty four gastric mucosal dysplasia patients with deficiency and excess correlation syndromes were enrolled by a multi-center collaboration for two years' clinical follow-up to detect the levels of tumor supplied group of factors (TSGF) and carcino-embryonic antigen (CEA). RESULTS: Among the 324 cases, 29 cases turned cancer in the two years, and the canceration rate was 9.0%. The three syndromes with higher canceration rate were the damp-heat accumulating Wei syndrome concurring or combining with asthenia-cold in Pi and Wei syndrome for 16.7%; stagnation in Wei collaterals syndrome concurring or combining with asthenia of both qi and yin syndrome for 13.2%; stagnation of Gan and Wei qi syndrome concurring or combining with asthenia-cold in Pi and Wei syndrome for 8.0%, respectively. Among the three syndromes, the highest level of TSGF occurred in the former two syndromes. In the half year before carcinogenesis, the syndromes of the patients took on deficiency and excess concurrent syndromes, and the deficiency syndromes involving the qi and blood deficiency syndrome and the Shen deficiency syndrome accounting for 48.0%. CONCLUSIONS: Gastric mucosal dyspalsia canceration syndromes took on the polymorphism of excess and deficiency concurrent syndromes and had the characteristics of deficiency syndromes involving qi and blood deficiency syndrome and Shen-yin-yang deficiency syndrome.

Effect of Jinguo Weikang Capsule on proto-oncogene expression of gastric mucosa in rats with gastric precancerous lesions.

OBJECTIVE: To study the effect of Jinguo Weikang Capsule [see text] on the gene expression of H-ras, epidermal growth factor receptor (EGFR), P53 and C-myc of the gastric mucosa in rats with gastric precancerous lesions, and to investigate the action mechanism of JWC on gastric precancerous lesions. METHODS: A rat model with paratypical proliferation of the gastric epithelium mucosa was established by using 60Co irradiation. Rats were divided into the normal group, model group, high-, medium-, low-dose JWC treatment groups, and the vitacoenzyme control group, and were treated for 30 days. The expression of H-ras, EGFR, P53 and C-myc genes of the gastric mucosa was detected by using immunohistochemical methods. RESULTS: The expression and over-expression rates of H-ras, EGFR, P53 and C-myc gene in the high-and medium-dose JWC treatment groups were significantly lower (P<0.05) as compared with those of the model group. CONCLUSION: JWC can inhibit the expression of the H-ras, EGFR, P53 and C-myc genes expression of the gastric mucosa in rats, which may be one of mechanisms involved in suppressing or reversing gastric carcinogenesis.

A clinical study of Suogudan granule in the treatment of rheumatoid arthritis.

OBJECTIVE: To study the clinical efficacy of Suogudan Granule (SGDG) in the treatment of rheumatoid arthritis (RA). METHODS: Ninety patients with RA were randomly divided into the treated group and the control group. The treated group was administered orally with SGDG 6 g each time, thrice a day, while the control group with the combined therapy of Fenbid Capsules 0.3 g each time, twice a day and Tripterygium tablet 20 mg each time, thrice a day. The treatment course for both groups was 6 weeks. The changes of clinical symptoms and signs, and laboratory indices such as erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), antistreptolysin O (ASO), routine examination of blood and urine, liver and kidney function, etc. before and after treatment were observed. RESULTS: (1) The total effective rate in the treated group (88.0%) was obviously higher than that in the control group (67.5%) with significant difference (P < 0.05). (2) The improvement in arthralgia, joint swelling, time of morning stiffness, 15-meter walking, analgesia initiation and persistence in the treated group was better than that in the control group (P < 0.05, P < 0.01), but there was no obvious difference in improvement of joint tenderness, range of joint motion, grip strength, and initiating detumescence time (P > 0.05). (3) The improvement in ESR and RF in the treated group was better than that in the control group with significant difference (P < 0.05). The negative-conversion rate of ASO in the treated group was also higher than that in the control group (P < 0.01). (4) No evident abnormality in blood, urine, liver or kidney function was found in either group. CONCLUSION: SGDG is effective and safe for the treatment of RA.