Objectives To study the effects of AT1 antagonist on MMP2, MMP9 expression and collagen remodeling in left ventricle of rabbit undergoing chronic pressure overload. Methods 30 rabbits were randomly divided into 3 grou...Objectives To study the effects of AT1 antagonist on MMP2, MMP9 expression and collagen remodeling in left ventricle of rabbit undergoing chronic pressure overload. Methods 30 rabbits were randomly divided into 3 groups ( n = 10, each group), including sham operation group, abdominal aorta banded group (banded group), abdominal aorta banded +valsartan group (valsartan group). Twelve weeks after operation, hemodynamic parameters were acquired, then collagen volume fraction (CVF) and MMP2, MMP9 expression of left ventricle were measured by using VG and immunohistochemical stain. Results Compared with sham operation group, both MMP2 and MMP9 expression were enhanced in banded group; meanwhile, LVW/BW, LVEDP and CVF increased significantly. Compared with banded group, both MMP2 and MMP9 expression were weakened in valarstan group; simultaneously, LVW/BW, LVEDP and CVF decreased significantly. Conclusions Expression of MMP2 and MMP9 was enhanced in left ventricle of rabbit undergoing chronic pressure overload, which may be associated with collagen proliferation, ventricule remodeling and impaired heart function; Valsartan could inhibit collagen proliferation, prevent ventricule remodeling and preserve heart function by inhibiting abnormal expression of MMP2 and MMP9.展开更多
Background Repeated attacks of bronchial asthma lead to different degrees of airway remodeling,the mechanism of which is not yet clear. Some evidences indicate that it is related to the excessive expression of some gr...Background Repeated attacks of bronchial asthma lead to different degrees of airway remodeling,the mechanism of which is not yet clear. Some evidences indicate that it is related to the excessive expression of some growth promotion factors. Angiotensin Ⅱ is a polypeptide that may be involved in airway remodeling. To evaluate its role in airway remodeling in asthma,we observed the effects of an angiotensin Ⅱ type 1 receptor antagonist (valsartan) on the expression of collagen Ⅲ,collagen Ⅴ,and transforming growth factor β_1 (TGF-β_1) mRNA and protein in the airway walls of sensitized rats.Methods Forty Wistar rats were randomly divided into 5 groups: control group,sensitized group,and valsartan groups 1,2,and 3. The rats in the sensitized group and in valsartan groups 1,2,and 3 were sensitized and challenged with ovalbumin. Rats in control group were sensitized and challenged with 0.9% NaCl. Rats from valsartan groups 1,2,and 3 were drenched with valsartan (10 μg, 20 μg,or 30 μg,respectively) at the time of the ovalbumin challenges. The expression of collagen Ⅲ,collagen Ⅴ,and TGF-β_1 protein were detected using immunohistochemical method in combination with image analysis methods. The expression of TGF-β_1 mRNA was detected by in situ hybridization. Results The expression in the airways of collagen Ⅲ and collagen Ⅴ was significantly higher in rats from the sensitized group (7.73±0.81, 1.34±0.28) and from valsartan groups 1,2,and 3 (5.73±0.64, 1.13±0.15; 4.96±0.51, 0.98±0.08; 4.43±0.35, 0.93±0.06,respectively) than those in the control group (2.65±0.38, 0.67±0.08,P <0.05). In addition,collagen levels were significantly lower in valsartan groups 1,2,and 3 than those from the sensitized group ( P <0.05). The expression of TGF-β_1 mRNA and protein in the airways was significantly higher in rats from the sensitized group (20.49%±3.46%,29.73%±3.25%) and from valsartan groups 1,2,and 3 (16.47%±1.94%, 19.41%±1.87%; 14.38%±1.58%, 18.29%±1.43%; 12.96%±1.73%, 18.63%±1.11%,respectively) than that from the control group (7.84%±1.61%, 5.63%±1.07%,P <0.05). TGF-β_1 mRNA and protein levels were significantly lower in valsartan groups 1,2,and 3 than that in the sensitized group ( P <0.05). Conclusions Angiotensin Ⅱ receptor antagonist valsartan can suppress synthesis of collagen Ⅲ and collagen Ⅴ by downregulating TGF-β_1 mRNA and protein expression. Valsartan can decrease airway remodeling and could play a role in asthma therapy.展开更多
文摘Objectives To study the effects of AT1 antagonist on MMP2, MMP9 expression and collagen remodeling in left ventricle of rabbit undergoing chronic pressure overload. Methods 30 rabbits were randomly divided into 3 groups ( n = 10, each group), including sham operation group, abdominal aorta banded group (banded group), abdominal aorta banded +valsartan group (valsartan group). Twelve weeks after operation, hemodynamic parameters were acquired, then collagen volume fraction (CVF) and MMP2, MMP9 expression of left ventricle were measured by using VG and immunohistochemical stain. Results Compared with sham operation group, both MMP2 and MMP9 expression were enhanced in banded group; meanwhile, LVW/BW, LVEDP and CVF increased significantly. Compared with banded group, both MMP2 and MMP9 expression were weakened in valarstan group; simultaneously, LVW/BW, LVEDP and CVF decreased significantly. Conclusions Expression of MMP2 and MMP9 was enhanced in left ventricle of rabbit undergoing chronic pressure overload, which may be associated with collagen proliferation, ventricule remodeling and impaired heart function; Valsartan could inhibit collagen proliferation, prevent ventricule remodeling and preserve heart function by inhibiting abnormal expression of MMP2 and MMP9.
基金ThisworkwassupportedbyagrantfromtheShanxiProvinceFoundationforReturnedOverseasChineseScholars (No 9913 -95 )
文摘Background Repeated attacks of bronchial asthma lead to different degrees of airway remodeling,the mechanism of which is not yet clear. Some evidences indicate that it is related to the excessive expression of some growth promotion factors. Angiotensin Ⅱ is a polypeptide that may be involved in airway remodeling. To evaluate its role in airway remodeling in asthma,we observed the effects of an angiotensin Ⅱ type 1 receptor antagonist (valsartan) on the expression of collagen Ⅲ,collagen Ⅴ,and transforming growth factor β_1 (TGF-β_1) mRNA and protein in the airway walls of sensitized rats.Methods Forty Wistar rats were randomly divided into 5 groups: control group,sensitized group,and valsartan groups 1,2,and 3. The rats in the sensitized group and in valsartan groups 1,2,and 3 were sensitized and challenged with ovalbumin. Rats in control group were sensitized and challenged with 0.9% NaCl. Rats from valsartan groups 1,2,and 3 were drenched with valsartan (10 μg, 20 μg,or 30 μg,respectively) at the time of the ovalbumin challenges. The expression of collagen Ⅲ,collagen Ⅴ,and TGF-β_1 protein were detected using immunohistochemical method in combination with image analysis methods. The expression of TGF-β_1 mRNA was detected by in situ hybridization. Results The expression in the airways of collagen Ⅲ and collagen Ⅴ was significantly higher in rats from the sensitized group (7.73±0.81, 1.34±0.28) and from valsartan groups 1,2,and 3 (5.73±0.64, 1.13±0.15; 4.96±0.51, 0.98±0.08; 4.43±0.35, 0.93±0.06,respectively) than those in the control group (2.65±0.38, 0.67±0.08,P <0.05). In addition,collagen levels were significantly lower in valsartan groups 1,2,and 3 than those from the sensitized group ( P <0.05). The expression of TGF-β_1 mRNA and protein in the airways was significantly higher in rats from the sensitized group (20.49%±3.46%,29.73%±3.25%) and from valsartan groups 1,2,and 3 (16.47%±1.94%, 19.41%±1.87%; 14.38%±1.58%, 18.29%±1.43%; 12.96%±1.73%, 18.63%±1.11%,respectively) than that from the control group (7.84%±1.61%, 5.63%±1.07%,P <0.05). TGF-β_1 mRNA and protein levels were significantly lower in valsartan groups 1,2,and 3 than that in the sensitized group ( P <0.05). Conclusions Angiotensin Ⅱ receptor antagonist valsartan can suppress synthesis of collagen Ⅲ and collagen Ⅴ by downregulating TGF-β_1 mRNA and protein expression. Valsartan can decrease airway remodeling and could play a role in asthma therapy.
