Influences of urinary kallidinogenase on neuronal apoptosis in cerebral infarction rats through Nrf2/ARE oxidative stress pathway.

OBJECTIVE: To investigate the influences of urinary kallidinogenase on neuronal apoptosis in rats with cerebral infarction through the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) oxidative stress pathway. MATERIALS AND METHODS: A total of 30 male rats were divided into group A (model control group), group B (rat model of cerebral infarction) and group C (rat model of cerebral infarction + medical treatment with urinary kallidinogenase). The percentage of cerebral infarct volume and the apoptosis of brain cells in the three groups of rats were detected via 2,3,5-Triphenyltetrazolium chloride (TTC) staining, the pathological morphology of brain tissues in the three groups of rats was observed via hematoxylin and eosin (HE) staining, and the protein levels of Nrf2 and superoxide dismutase 1 (SOD1) in the brain tissues in the three groups of rats were measured using the Western blotting assay. RESULTS: The degree of neurological deficit in group B was remarkably higher than that in group A (p<0.05), and it was markedly decreased in group C compared to that in group B, displaying statistically significant differences (p<0.05). Compared to that in group A, the cell apoptosis was significantly aggravated in group B, while a remarkably alleviated cell apoptosis was observed in group C compared to that of group B, and the differences were statistically significant (p<0.05). The cerebral infarct volume accounted for 34.87% of the whole brain volume in group B, and a mild cerebral infarction was detected in group C, with a percentage of cerebral infarct volume of 21.14%. Group B showed a more evident increase in the cerebral infarct volume than in group C (p<0.05). Compared to those of group A, pyknotic nuclei and neuron staining of brain tissue cells were evidently increased, and the neuronal cell injury was aggravated in group B. Moreover, prominently decreased pyknotic nuclei and neuron staining (p<0.05) as well as mild neuronal cell injury (p<0.05) were detected in group C compared to those in group B. The levels of Nrf2 and SOD1 protein in the brain tissues in group B were remarkably lower than those of group C (p<0.05). CONCLUSIONS: Urinary kallidinogenase can inhibit the neuronal apoptosis in rats and protect the rats from cerebral infarction, whose mechanism is associated with the activation of the Nrf2/ARE oxidative stress pathway.

MiR-7 alleviates secondary inflammatory response of microglia caused by cerebral hemorrhage through inhibiting TLR4 expression.

OBJECTIVE: This study was conducted to analyze the effect of miR-7 on the inflammatory response of microglia in vitro and in vivo by constructing an intracerebral hemorrhage model. PATIENTS AND METHODS: In this study, we first established a model of cerebral hemorrhage in rat for in vivo experiments, and used lipoprotein (LPS) to induce an inflammatory response development in microglial cells, and constructed microglial inflammation models for in vitro experiments. Quantitative Real-time-polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-7 in the rat model of cerebral hemorrhage and microglia with inflammation. The effect of miR-7 on the inflammation caused by intracerebral hemorrhage was evaluated through measuring the expression of IL-1ß, IL-8 and TNF-α by enzyme-linked immunosorbent assay (ELISA). Dual luciferase reporter assay was used to detect the binding site of miR-7 to TLR4. Western blot was used to evaluate the level of TLR4 after overexpression and knockdown of miR-7 and to evaluate whether miR-7 alleviated the secondary inflammatory response of microglia after cerebral hemorrhage by inhibiting the expression of TLR4. RESULTS: The expression of miR-7 in the rat cerebral hemorrhage model and microglial inflammation model tissue was significantly lower than that in the normal control group. Expression of inflammatory cytokines including IL-1ß, IL-8 and TNF-α was significantly increased in rats with intracerebral hemorrhage and microglial inflammation in rats, and the expression of these inflammatory cytokines was partially reversed after overexpression of miR-7. Double luciferase reporter gene and ELISA results showed that miR-7 could inhibit the expression of TLR4 and relieve the secondary inflammatory response of microglia after cerebral hemorrhage. CONCLUSIONS: We demonstrated that, in in vivo and in vitro experiments, miR-7 could reduce the LPS-induced inflammatory response produced by microglial cells, and alleviate the inflammation in the brain of rats with cerebral hemorrhage.

Notch ligand Delta-like 1 promotes the metastasis of melanoma by enhancing tumor adhesion.

Notch signaling plays a vital role in tumorigenicity and tumor progression by regulating proliferation, invasion, and the tumor microenvironment. Previous research by our group indicated that Notch ligand Delta-like 1 (Dll1) is involved in angiogenesis in melanoma, and we noticed that it took a longer time to trypsinize Dll1-expressing B16 melanoma cells than the control cells. In this article, we extended our study to investigate the effects of Dll1 on tumor cell adhesion and metastasis. Dll1 overexpression activated Notch signaling in B16 tumor cells and significantly enhanced the adhering capacity of B16 tumor cells both in vitro and in vivo. B16-Dll1 cells also had a higher metastatic potential than their counterpart in the mouse model of lung metastasis. Along with increased Dll1 expression, N-cadherin, but not E-cadherin, was upregulated in B16-Dll1 cells. These data suggested that Notch ligand Dll1 may enhance the adhesion and metastasis of melanoma cells by upregulation of N-cadherin.

Notch ligand Delta-like 1 promotes the metastasis of melanoma by enhancing tumor adhesion

Notch signaling plays a vital role in tumorigenicity and tumor progression by regulating proliferation, invasion, and the tumor microenvironment. Previous research by our group indicated that Notch ligand Delta-like 1 (Dll1) is involved in angiogenesis in melanoma, and we noticed that it took a longer time to trypsinize Dll1-expressing B16 melanoma cells than the control cells. In this article, we extended our study to investigate the effects of Dll1 on tumor cell adhesion and metastasis. Dll1 overexpression activated Notch signaling in B16 tumor cells and significantly enhanced the adhering capacity of B16 tumor cells both in vitro and in vivo. B16-Dll1 cells also had a higher metastatic potential than their counterpart in the mouse model of lung metastasis. Along with increased Dll1 expression, N-cadherin, but not E-cadherin, was upregulated in B16-Dll1 cells. These data suggested that Notch ligand Dll1 may enhance the adhesion and metastasis of melanoma cells by upregulation of N-cadherin.

Combined effects of prenatal inhibition of vasculogenesis and neurogenesis on rat brain development.

Malformations of cortical development (MCD) are one of the most common causes of neurological disabilities including autism and epilepsy. To disrupt cortical formation, methylazoxymethanol (MAM) or thalidomide (THAL) has been used to affect neurogenesis or vasculogenesis. Although previous models of MCD have been useful, these models primarily attack a single aspect of cortical development. We hypothesized that simultaneous prenatal exposure to MAM or THAL will lead to the development of a novel and specific type of brain maldevelopment. Rats were prenatally exposed to MAM and THAL. At early postnatal days, brains displayed abnormal ventricular size and hemispheric asymmetry due to altered brain water homeostasis. The postnatal brain was also characterized by gliosis in regions of focal leakage of the blood brain barrier. These morphological abnormalities gradually disappeared at adult stages. Although the adult MAM-THAL rats showed normal cortical morphology, abnormal hippocampal connectivity and mossy fiber sprouting persisted well into adulthood.

Preliminary report on treatment of bone tumors with microwave-induced hyperthermia.

Between July, 1992, and February, 1995, 62 patients with various bone tumors were treated with microwave-induced hyperthermia. The series had 47 cases of malignant tumors and 15 cases with benign tumors; most of the tumors occurred at or near knee joints (53/62 = 85.4%). The surgical procedure consisted of separating the tumorous segment from surrounding normal tissues with a safe margin, cooling the normal tissues (including the vital neurovascular bundle and the intrajoint structures) with a water circulation system while heating the tumor simultaneously with the microwave antenna array, and providing an adequate soft-tissue cover for the dead bone. The tumor core temperature and the surface temperature reached 108 and 65 degrees C, respectively. The duration of microwave irradiation was usually 40-50 minutes. Meanwhile, the temperature of the normal tissues was kept under 39 degrees C. The minimal and maximal periods of clinical observation were 3 months and 36 months, respectively, and the mean follow-up period was 17 months. The 62 cases were evaluated from both oncological and orthopedic points of view. Five cases had local recurrence and required amputation. The 57 other cases had excellent local control. Six malignancy cases died of lung metastasis during a period of 1-2 years. Pathological fracture occurred at devitalized bone in five cases. In most of the cases, the knee joints functioned well, were stable and painless, and had almost full range of motion. Single-photon emission-computed tomography study in 16 cases revealed that revascularization of the devitalized tumorous bone segment could be accomplished in 1 year or more. These results show that the use of microwave hyperthermia for the treatment of bone tumors can be considered to be a definitive operation procedure that is safe and is well tolerated by patients. The oncological and orthopedic results are very encouraging.

Repair of a huge defect of the gluteal region by rotation of a combined tensor fasciae latae-sartorius myocutaneous flap.

Although the tensor fasciae latae myocutaneous flap is convenient for covering some defects in the gluteal region, it is not suitable to repair a huge defect because of its limited area. Based on the close relationship of the sartorius and the tensor fasciae latae at their origins and blood supply, the authors designed a myocutaneous flap containing both the tensor fasciae latae and the sartorius muscles and their skin territories with an area exceeding 800 cm2. Two successfully repaired patients are reported. The flaps provide normal sensitivity. The vascular pedicle has a reliable anatomy, being easily dissected, and averages 4.6 to 5.8 cm in length. Both muscles are expendable. There is little functional difficulty for hip joint after the operation.

The study of giant cell tumors in bone.

Twelve samples of giant cell tumor of bone were incubated in the authors' laboratory. The activity of the cells was documented by means of time lapse cinemicrography. The multinuclear giant cells (MGCs) with undegenerating nuclei migrating from the explants had active ameboid movement and continuously changed their shapes. The majority of them kept splitting themselves into smaller MGCs until mononuclear cells formed, which were indistinguishable from the original stromal cells in morphology and could take up tritiated thymidine as shown by autoradiography. This splitting process of MGCs is mainly responsible for their vanishing in culture. The authors believe that an MGC is one of the true neoplastic elements. MGCs are present merely in the form of a syncytium derived from neoplastic stromal cells. In culture, the factors maintaining the syncytium are lost and the process opposite to cell fusion appears. Therefore, from a morphological view, MGCs and neoplastic stromal cells are homologous.