Effect of HGF gene transfection on human lymphoma xenografts in nude mice

AIM：To explore the promotion effect of hepatocyte growth factor (HGF) gene transfection on human lymphoma xenografts in nude mice. METHODS：The model of human lymphoma xenograft in nude mice was established by transplantation of Raji cells, which were transfected with recombinant plasmid pVITRO2-HGF harboring the HGF gene. The body weight of the nude mice and the tumor size were dynamically monitored and the tumor tissues were obtained after 8 weeks. Additionally, the methods of terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) and immunohistochemistry were used to detect the apoptotic index (AI) and microvessel density (MVD). RESULTS：The success rate of the human lymphoma xenografts in nude mice was 96.7%. The tumor volume in HGF transfection group was significantly greater than that in HGF transfection+VP-16 group and control groups (non-transfection group and empty vector group). The tumor volume in HGF transfection+VP-16 group was also bigger than that in control groups. No difference of the tumor volume between non-transfection group and empty vector group was observed. AI in HGF transfection group was substantially lower than that in control groups. AI in HGF transfection+VP-16 group showed a little higher than that in HGF transfection group, yet was still lower than that in control groups. MVD in HGF transfection group was extraordinary higher than that in control groups, but decreased after VP-16 induction (P<0.01), which was still higher than that in control groups. CONCLUSION：HGF gene transfection significantly promotes the growth of human lymphoma xenografts in nude mice and substantially inhibits the apoptosis presumably owing to promoting tumor angiogenesis and inhibiting tumor cell apoptosis.     

Expression of apoptosis signal protein induced by Fas in labial salivary gland of patients with primary Sjgren’s syndrome

AIM:To study the expression of apoptosis signal proteins induced by Fas in labial salivary gland of patients with primary Sjgren’s syndrome (pSS), and investigate the possible pathway of the cell signaling transduction in pSS. METHODS:Biopsies of minor submucosal labial salivary gland were obtained from 32 patients with pSS and 8 normal controls. Fas, FasL and FADD were detected by Western blotting. Caspase-3 was measured by immunohistochemistry and CAD mRNA expression was determined by RT-PCR. RESULTS:The expressions of Fas, FasL, FADD, caspase-3 and CAD mRNA in labial salivary glands of patients with pSS were significantly higher than those in control group (P＜0.05). CONCLUSION:The apoptosis signalling transduction in labial salivary glands of patients with pSS may be that the product of FasL combined with Fas activates caspase-8 through FADD, then ICE family is cascaded, and finally CAD is splited by caspase-3 from ICAD, which catalyzes the degradation of DNA.      

Vasodilatation induced by Jumi extraction and its mechanisms

AIM: The objectives of the present study were to examine the effect of Jumi (JM) extraction on relaxation of isolated rat aortic rings, and to elucidate its mechanisms. METHODS: The thoracic aortic rings with and without endothelium of male Sprague-Dawley rats were mounted on a bath system. Vasodilatation of aortic rings preconstricted with 10-6 mol/L of phenylephrine (PE) was measured. RESULTS: JM extraction (0.5-8 g/L) caused a concentration-dependent relaxation in aortic rings. The extent of relaxation was larger in endothelium-intact aortic rings than that in endothelium-denuded aortic rings. Both L-NAME［a nitric oxide synthase (NOS) inhibitor］ and high potassium (20 mmol/L KCl) partly abolished the relaxation action of JM extraction in endothelium-intact aortic rings. Pretreatment with L-NAME also inhibited the relaxation response to JM extraction in endothelium-denuded aortic rings. After incubation with JM extraction, NOS activities enhanced both in endothelium-intact and endothelium-denuded aortic rings. CONCLUSION: JM extraction causes relaxation of aortic rings through endothelium-dependent and independent pathways. The mechanisms might be involved in NOS and endothelium-derived hyperpolarizing factor.     

Effect of propofol on expression of PKC mRNA in pulmonary injury induced by ischemia-reperfusion in rabbits

AIM: To investigate the effect of propofol on expression of protein kinase C (PKC) mRNA during pulmonary ischemia and reperfusion injury (PIRI) in rabbits. METHODS: Single lung ischemia and reperfusion animal model was used in vivo. The rabbits were randomly divided into three groups (n=9 in each): sham operated group (sham), PIR group (I-R) and PIR+ propofol group (PPF). Changes of several parameters including malondialdehyde (MDA), superoxide dismutase (SOD), wet to dry ratio of lung tissue weight (W/D) and index of quantitative assessment of histologic lung injury (IQA) were measured at 60 minutes after reperfusion in lung tissue. Meanwhile the location and expression of PKC mRNA were observed. Lung tissue was also prepared for light microscopic and electron microscopic observation at 60 minutes after reperfusion. RESULTS: As compared with group I-R, PKC mRNA strongly expressed in intima and extima of small pulmonary artery as well as thin-wall vessels (mostly small pulmonary veins) in PPF group. The average optical density values of PKC-α、δ and θ mRNA in small pulmonary veins PPF in group showed significantly higher than that in I-R group (all P<0.01). SOD increased and MDA, W/D and IQA decreased at 60 minutes after reperfusion in lung tissue (P<0.01 and P<0.05). Abnormal changes of the lung tissue in morphology were lessen markedly in PPF group. CONCLUSIONS: Propofol produces notable protective effects on PIRI in rabbits by activating PKC-α， δ and θ mRNA expression in lung tissue, raising NO level, dropping OFR level and decreasing lipid peroxidation.     

Role of heme oxygenase-1/carbon monoxide system in pulmonary ischemia-reperfusion injury

AIM: To investigate the effect of heme oxygenase-1 (HO-1)/carbon monoxide (CO) system on pulmonary ischemia-reperfusion injury (PIRI) in rabbits. METHODS: Single lung ischemia and reperfusion animal model was used in vivo. The rabbits were randomly divided into three groups (n=10 in each), control group (C), PIR group (I-R), PIR+ hemin group (H) and PIR+zinc protoporphyrin IX (ZnPP) group (Z). Changes of several parameters which included plasma carboxyhemoglobin (COHb) at different time points, wet to dry ratio of lung tissue weight (W/D), the injured alveoli rate (IAR) and the HO-1 enzymatic activity were measured at 180 min after reperfusion in lung tissue. The tissue slides were also stained by immunohistochemistry (IHC) and in situ hybridization (ISH) for HO-1 to detect the expression of HO-1 in lung and to analyze the optical density. The lung tissue was prepared for electron microscopic observation at 180 min after reperfusion. RESULTS: The plasma content of COHb in I-R, H, and Z group increased in a time-dependent manner after I-R. But the increment of H group was higher than that of I-R group, while that of Z group was lower. The HO-1 activity in lung tissue was highest in H group, followed by IR group, Z group, and C group (P<0.05 and P<0.01). Except C group, HO-1 was upregulated in all other groups in the pulmonary endothelial cells, part of pulmonary vascular smooth muscle cells, extima of vessels and epithelial cells of airway. H group had the highest average optical density value, then the IR group, Z group and C group (P<0.05 and P<0.01). The value of W/D and IAR was highest in Z group, the second was in IR group, then the H group and C group (P<0.05 and P<0.01). The abnormal changes of the lung tissue in morphology in I-R group, Hemin treatment mitigated the injury of I-R in H group and ZnPP exacerbated the impairment of ultrastructure in Z group were also observed. CONCLUSION: HO-1/CO system possesses notable protective effects on lung during pulmonary ischemia-reperfusion injury in rabbits.     

Expression of MMP-2 mRNA and MMP-9 mRNA in pulmonary arterioles ofrats with pulmonary hypertension induced by chronic hypoxia hypercapnia

AIM:To investigate the expression of matrix metalloproteinases(MMPs) in pulmonary arterioles of rats with chronic hypoxia and hypercapnia-induced pulmonary hypertension.METHODS:MMP-2, MMP-9 and MMP-2 mRNA, MMP-9 mRNA were observed in pulmonary arterioles by the techniques of immunohistochemistry and in situ hybridization.RESULTS:①The mean pulmonary artery pressure (mPAP) and weight ratio of right ventricle to left ventricle and septum (RV/LV+S) of hypoxia-hypercapnia groups were higher than those of normal control group (P＜0.01). ②Light microscopy showed that vessel wall and media of pulmonary arterioles were thicker in rats of hypoxia-hypercapnia groups than normal control group. There were vessel smooth muscle cell hypertrophy, vessel cavity straitness in hypoxia-hypercapnia group, but no same performance was found in normal control group. ③The expression of MMP-2, MMP-9 and MMP-2 mRNA, MMP-9 mRNA in pulmonary arterioles were significantly higher in rats of hypoxia-hypercapnia groups than control group (P＜0.01).CONCLUSION:Expression of matrix metalloproteinases in pulmonary arterioles is enhanced by hypoxia hypercapnia. This may be involved in pulmonary vascular remodeling in rats with pulmonary hypertension.     

The activative effect of Paecilomyces cicadaeon peritoneal and alveolar macrophages of rats

AIM:To explore the activative effect of water extract from cultured mycelium ofPaecilomyces cicadae (P. cicadae)on peritoneal macrophages (PMΦ) and alveolar macrophages (AMΦ) of rats.METHODS:The rats were randomly divided into four groups: normal control group(Ⅰ), cyclophosphamide (Cy) group (Ⅱ),P. cicadaegroup(Ⅲ), Cy+P.cicadaegroup(Ⅳ).The rats were bred in the same circumstance and were administered with corresponding drugs by subcutaneous injection for 26 days. PMΦ and AMΦ of rats were irrigated by normal saline and collected by centrifuge and incubated in a humidified incubator for 2 h at 37 ℃. The activities of acid phosphatase (ACP) and lactate dehydrogenase (LDH) in the PMΦ and AMΦ were determined by biochemical methods, and the capability of PMΦ and AMΦ in phagocytosis of neutral red were measured by colorimetric method too. RESULTS:After administering P. cicadaeto rats, the activities of ACP and LDH in PMΦ and AMΦ of normal rats were elevated significantly,and the reduction of the activities of ACP and LDH in PMΦ and AMΦ of rats due to Cy was notably antagonized, and the capability of PMΦ and AMΦ phagocytizing the neutral red were strengthened significantly.CONCLUSION:P. cicadaecan activate the PMΦ and AMΦ of rats.     

Effect of endoplasmic reticulum stress on brain injury following chronic intermittent hypoxia in growing rats

AIM: To explore the role of endoplasmic reticulum stress (ERS) in brain injury following chronic intermittent hypoxia in growing rats and the protective effect of treatment with salubrinal. METHODS: Healthy male SD rats (3~4-week-old, 100~120 g, n=64) were randomly assigned to 8 groups (8 rats in each group):the groups of intermittent hypoxia for 2 and 4 weeks (2IH and 4IH), the groups of control (C) for 2 and 4 weeks (2C and 4C), the groups of dimethylsulfoxide (DMSO) for 2 and 4 weeks (2DMSO and 4DMSO) and the groups of salubrinal for 2 and 4 weeks (2SAL and 4SAL). The 8-arm radial maze was used to assess the working memory error (WME), reference memory error (RME) and total error (TE) of the rats. The changes of neuronal apoptosis in the hippocampus were observed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The activity of superoxide dismutase (SOD), and the protein levels of endoplasmic reticulum stress marker compounds, C/EBP homologous protein (CHOP), phosphorylated eukaryotic translation initiation factor 2 alpha (p-eIF2α) and phosphorylated protein kinase R-like endoplasmic reticulum kinase (p-PERK), were analyzed. RESULTS: Chronic intermittent hypoxia (CIH) significantly increased RME, WME, TE and neuronal apoptotic index (AI) (P<0.01), and decreased the activity of SOD in the hippocampus and serum (P<0.01). The protein levels of p-PERK and CHOP progressively increased in hippocampus in IH groups (P<0.01), and p-eIF2α was downregulated (P<0.05). Treatment with salubrinal significantly decreased RME (P<0.05), WME (P<0.05), TE (P<0.01) and AI (P<0.01), and increased the activity of SOD (P<0.01). Salubrinal induced the phosphorylation of eIF2α significantly after CIH in hippocampus and downregulated the level of CHOP (P<0.01). CONCLUSION: Chronic intermittent hypoxia upregulates the protein levels of p-PERK and CHOP in the hippocampus, and decreases p-eIF2α protein and the activity of SOD. Salubrinal, a selective inhibitor of eIF-2α dephosphorylation, increases the activity of SOD and prevents CHOP protein activation throughout CIH exposure. Our findings suggest ERS-mediated cell apoptosis is one of the underlying mechanisms of cognitive dysfunction in OSAHS children. Further, a specific ERS inhibitor salubrinal should be tested for neuroprotection against CIH-induced brain injury.     

Effect of caveolin-1 expression on high-salt diet-induced endothelial dysfunction in type 1 diabetic rats

AIM: To investigate the underlying mechanisms responsible for endothelial dysfunction of type 1 diabetes mellitus (DM) rats fed with high-salt diet. METHODS: Type 1 DM was induced by intraperitoneal injection of streptozotocin (70 mg/kg). Normal and diabetic rats were fed high-salt food (HS, 8% NaCl) and standard food for 6 weeks, respectively. Isometric tension of the mesenteric arteries were measured. The expression of Akt, endothelial nitric oxide synthase (eNOS) and caveolin-1 (Cav-1) was examined by Western blot. RESULTS: The rats in DM+HS group exhibited more pronounced impairment of vasorelaxation to acetylcholine and insulin compared with either DM group or HS group (P<0.01). Akt and eNOS phosphorylation levels, and nitric oxide (NO) concentration in DM+HS group were significantly lower than those in DM group (P<0.01). The level of Cav-1 in DM+HS group was significantly higher than that in DM group and HS group. CONCLUSION: Impaired endothelial Akt activation, increased Cav-1 expression and resultant decreased eNOS activation contribute to aggravate high-salt diet-induced endothelial dysfunction and hypertension in DM rats.