Angiotensin II induces expression of inflammatory mediators in vascular adventitial fibroblasts / 生理学报

Vascular adventitial fibroblasts (AF) may play an important role in vascular inflammation. This study was aimed to investigate the expression pattern of inflammatory mediators in AF induced by angiotensin II (AngII) and to explore the effects of AF-derived inflammatory mediators on the adhesion and migration of macrophages both in vitro and in vivo. We used real-time RT-PCR to detect the mRNA expression of inflammatory mediators in cultured AF. The results showed that AngII (1 × 10(-7) mol/L) up-regulated mRNA expression of 4 inflammatory mediators, including P-selectin, ICAM-1, IL-6 and MCP-1, in cultured AF. Western blot analysis or ELISA revealed that AngII up-regulated P-selectin and ICAM-1 protein expression and IL-6 secretion in cultured AF, but did not alter MCP-1 secretion. We further detected the effects of AF-derived inflammatory mediators on the adhesion and chemotaxis of RAW264.7, a macrophage cell line. We found that AF stimulated with AngII could enhance the adhesion of RAW264.7 and the conditioned medium from AngII-stimulated AF could enhance the migration of RAW264.7. Immunofluorescence study showed an enhanced accumulation of CD68 positive cells and the up-regulation of P-selectin, ICAM-1, IL-6 and MCP-1 in aortic adventitia of AngII-infused (200 ng/kg per min for 2 weeks) rats. We concluded that AF may contribute to vascular inflammation via expression of certain inflammatory mediators and the subsequent adhesion and chemotaxis of macrophages.

RhoA-Rho kinase signaling pathway mediates adventitial fibroblasts differentiation to myofibroblasts induced by TGF-β1 / 生理学报

Vascular adventitial fibroblasts (AF) differentiation to myofibroblasts (MF) is the critical physiopathologic feature of vascular remodeling. This study was to investigate the role of RhoA-Rho kinase signaling pathway in AF differentiation to MF induced by transforming growth factor β1 (TGF-β1). The results showed that TGF-β1 up-regulated total RhoA protein expression and RhoA activity in cultured AF by Western blotting and Rho pull-down assay, respectively. TGF-β1 up-regulated phospho-Myosin phosphatase target subunit (MYPT1, a downstream substrate of Rho kinase) expression without altering Rho kinase protein expression, indicating TGF-β1 induced the enhancement of activity of Rho kinase. Ad-N19RhoA-hrGFP virus infection and Y27632, a specific inhibitor of Rho kinase, dose-dependently inhibited TGF-β1-induced α-SM-actin and Calponin expression, as markers of MF differentiation. In conclusion, the RhoA-Rho kinase pathway is involved in AF differentiation to MF induced by TGF-β1.

Adenovirus mediated N19RhoA gene transfer attenuates neointimal formation in rats after carotid artery balloon injury / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the role of small G-protein RhoA in neointimal formation following rat carotid artery balloon injury and related mechanisms.</p><p><b>METHODS</b>Male 3-4-month-old Sprague-Dawley rats were used in the present study (10 rats per group). Group A: control; Group B: carotid artery balloon injury; Group C: injury + Ad-CMV-eGFP + Pluronic F-127; Group D: injury + Ad-CMV-N19RhoA-eGFP + Pluronic F-127; Group E: non injury + Ad-CMV-eGFP + Pluronic F-127. Perivascular gene transfer of an adenovirus co-expressing N19RhoA was performed to rat carotid artery following balloon injury and the effect on neointimal formation and the expressions of PCNA and α-SM-actin examined. Rats were killed after 14 days.</p><p><b>RESULTS</b>The protein expression of RhoA in group B was significantly higher than in group A (P = 0.001), and the positive cells rate of PCNA and α-SM-actin which were assessed by immunohistochemistry in group C (45.2% and 75.6%) was significantly higher than in group D (28.4% and 51.9%, all P < 0.01). The area of neointima was significantly smaller [(0.14 ± 0.08) mm(2) vs. (0.23 ± 0.10) mm(2), P < 0.01], the luminal area was significantly larger [(0.47 ± 0.11) mm(2) vs. (0.31 ± 0.06) mm(2), P < 0.01] in group D than in group C.</p><p><b>CONCLUSION</b>Gene transfer of N19RhoA attenuates neointimal formation after balloon injury in rat carotid arteries possibly related to the modulating capacities of small G-protein RhoA on the proliferation, phenotypic differentiation and migration of vascular adventitial fibroblasts.</p>

Effects of high-volume hemofiltration on alveolar-arterial oxygen exchange in patients with refractory septic shock / 世界急诊医学杂志（英文）

@#BACKGROUND: High-volume hemofiltration (HVHF) is technically possible in severe acute pancreatitis (SAP) patients complicated with multiple organ dysfunction syndrome (MODS). Continuous HVHF is expected to become a beneficial adjunct therapy for SAP complicated with MODS. In this study, we aimed to explore the effects of fluid resuscitation and HVHF on alveolar-arterial oxygen exchange, the Acute Physiology and Chronic Health Evaluation II (APACHE II) score in patients with refractory septic shock. METHODS: A total of 89 refractory septic shock patients, who were admitted to ICU, the Provincial Hospital affiliated to Shandong University from August 2006 to December 2009, were enrolled in this retrospective study. The patients were randomly divided into two groups: fluid resuscitation (group A, n=41), and fluid resuscitation plus high-volume hemofiltration (group B, n=48). The levels of O2 content of central venous blood (CcvO2), arterial oxygen content (CaO2), alveolar-arterial oxygen pressure difference P(A-a)DO2, ratio of arterial oxygen pressure/alveolar oxygen pressure (PaO2/PAO2), respiratory index (RI) and oxygenation index (OI) were determined. The oxygen exchange levels of the two groups were examined based on the arterial blood gas analysis at different times (0, 24, 72 hours and 7 days of treatment) in the two groups. The APACHE II score was calculated before and after 7-day treatment in the two groups. RESULTS: The levels of CcvO2, CaO2 on day 7 in group A were significantly lower than those in group B (CcvO2: 0.60±0.24 vs. 0.72±0.28, P<0.05; CaO2: 0.84±0.43 vs. 0.94±0.46, P<0.05). The level of oxygen extraction rate (O2ER) in group A on the 7th day was significantly higher than that in group B ( 28.7±2.4 vs. 21.7±3.4, P<0.01). The levels of P(A-a)DO2 and RI in group B on the 7th day were significantly lower than those in group A. The levels of PaO2/PAO2 and OI in group B on 7th day were significantly higher than those in group A (P<0.05 or P<0.01). The APACHE II score in the two groups reduced gradually after 7-day treatment, and the APACHE II score on the 7th day in group B was significantly lower than that in group A (8.2±3.8 vs. 17.2±6.8, P<0.01). CONCLUSION: HVHF combined with fluid resuscitation can improve alveolar- arterial-oxygen exchange, decrease the APACHE II score in patients with refractory septic shock, and thus it increases the survival rate of patients.