目的:探讨Perlecan蛋白在子痫前期(PE)小鼠肾脏中的变化及其作用机制。方法:构建正常孕鼠、PE样小鼠模型(动物水平)及HSPG2特异性肾敲低小鼠模型并分离肾小球内皮细胞(细胞水平),对比观察小鼠肾脏基底膜负电荷改变、Perlecan蛋白及其降...目的:探讨Perlecan蛋白在子痫前期(PE)小鼠肾脏中的变化及其作用机制。方法:构建正常孕鼠、PE样小鼠模型(动物水平)及HSPG2特异性肾敲低小鼠模型并分离肾小球内皮细胞(细胞水平),对比观察小鼠肾脏基底膜负电荷改变、Perlecan蛋白及其降解酶Hpa含量变化,同时检测PI3K/AKT/mTOR信号通路相关蛋白以及自噬蛋白标志物的含量。结果:(1)成功构建了PE小鼠和HSPG2条件肾敲低小鼠模型。(2)相对于正常孕鼠,PE小鼠胶体铁染色显示负电荷基本消失,肾小球电荷屏障被破坏,蛋白免疫印迹结果显示PE小鼠肾小球中Perlecan蛋白表达(0.255±0.028)较正常孕鼠(0.509±0.022)显著降低;而Hpa表达(0.519±0.041)较正常孕鼠(0.260±0.063)显著升高(P均<0.05)。(3)与正常孕鼠相比,PE小鼠PI3K/AKT/mTOR信号通路相关蛋白PI3K(0.146±0.018 vs 0.448±0.048)、p-AKT(0.031±0.008 vs 0.286±0.030)和p-mTOR(0.179±0.029 vs0.364±0.025)表达显著下调,自噬相关标志物LC3-I/LC3-Ⅱ(0.546±0.060 vs 0.244±0.060)和Beclin-1(0.527±0.029 vs 0.191±0.044)表达显著升高,差异均有统计学意义(P均<0.05);PI3K/AKT/mTOR通路药理激活剂740 Y-P和MHY1485可以有效地弥补Perlecan敲低引起的自噬增加。结论:PE小鼠Perlecan蛋白下降除外引起肾小球电荷屏障损伤,还可能通过抑制PI3K/AKT/mTOR信号通路来促进细胞自噬引起肾脏血管内皮细胞损伤。展开更多
The present study observed sciatic nerve and gastrocnemius muscle changes in denervated rats using morphology methods, and assessed expression of perlecan, an extracellular matrix component, which is located at the sk...The present study observed sciatic nerve and gastrocnemius muscle changes in denervated rats using morphology methods, and assessed expression of perlecan, an extracellular matrix component, which is located at the skeletal muscle cell surface as acetylcholine esterase, as well as synaptophysin, a synaptic marker. Results showed degeneration and inflammation following transection of the sciatic nerve. In addition, the sciatic nerve-dominated skeletal muscle degenerated with mild inflammation, indicating that skeletal muscle atrophy primarily contributed to denervation-induced nutritional disturbances. With prolonged injury time （1-4 weeks post-injury）, perlecan expression gradually decreased and reached the lowest level at 4 weeks, but synaptophysin expression remained unchanged after denervation. Results suggested that perlecan expression was more sensitive to denervation and reflected regional extracellular matrix changes following denervation.展开更多
Perlecan,a heparan sulfate proteoglycan,acts as a mechanical sensor for bone to detect external loading.Deficiency of perlecan increases the risk of osteoporosis in patients with Schwartz-Jampel Syndrome(SJS)and atten...Perlecan,a heparan sulfate proteoglycan,acts as a mechanical sensor for bone to detect external loading.Deficiency of perlecan increases the risk of osteoporosis in patients with Schwartz-Jampel Syndrome(SJS)and attenuates loading4nduced bone formation in perlecan deficient mice(Hypo).Considering that intracellular calcium[Ca2+]i is an ubiquitous messenger controlling numerous cellular processes including mechanotransduction,we hypothesized that perlecan deficiency impairs bone’s calcium signaling in response to loading.To test this,we performed real-time[Ca2+]i imaging on in situ osteocytes of adult murine tibiae under cyclic loading(8 N,Figure 1).Relative to wild type(WT),Hypo osteocytes showed decreases in the overall[Ca2+]i response rate(-58%),calcium peaks(-33%),cells with multiple peaks(-53%),peak magnitude(-6.8%),and recovery speed to baseline(-23%).RNA sequencing and pathway analysis of tibiae from mice subjected to one or seven days of unilateral loading demonstrated that perlecan deficiency significantly suppressed the calcium signaling,ECM-receptor interaction,and focal adhesion pathways following repetitive loading.Defects in the endoplasmic reticulum(ER)calcium cycling regulators such as Ryr1/ryanodine receptors and Atp2a1/Sercal calcium pumps were identified in Hypo bones.Taken together,impaired calcium signaling may contribute to bone’s reduced anabolic response to loading,underlying the osteoporosis risk for the SJS patients.展开更多
Lens fibre differentiation is a life-long process related with lens transparency, and is particularly intense during development, being related with an FGF-2 antero-posterior gradient at the equator level as the main ...Lens fibre differentiation is a life-long process related with lens transparency, and is particularly intense during development, being related with an FGF-2 antero-posterior gradient at the equator level as the main growth factor involved which has been related with the basal membrane of the lens anlagen known as “Lens capsule”. However the lens fibre differentiation induced by FGF2 depends, as in other biological systems, on the local bioavailability of FGF-2 regulated by their relationship with extracellular matrix molecules as Heparan Sulphate Proteoglycans. Here, we try to clarify how Perlecan (a heparan sulphate proteoglycan specific from basement membranes) is involved in lens fibre differentiation at earliest stages of eye development. Our results show that Perlecan, is a major component in the lens capsule during the earliest stages of lens development in chick embryos being present during lens plate induction, lens vesicle stage and the onset of lens fibre differentiation. In order to demonstrate a direct involvement of HSPG-Perlecan in lens fibre differentiation, we generate depleted lenses by HSPG-Perlecan synthesis disruption and specific enzymatic digestion. The HSPG-Perlecan depleted lens show a significant delay or abolition in the lens fibre differentiation which remains in an immature cells displaying DNA synthesis in the posterior epithelium and a decrease in FGF2 lens expression. These data support the hypothesis that lens capsule HSPG-Perlecan is a key molecule involved in lens fibre differentiation during development, probably by involvement in FGF-2 biodisponibility.展开更多
文摘目的:探讨Perlecan蛋白在子痫前期(PE)小鼠肾脏中的变化及其作用机制。方法:构建正常孕鼠、PE样小鼠模型(动物水平)及HSPG2特异性肾敲低小鼠模型并分离肾小球内皮细胞(细胞水平),对比观察小鼠肾脏基底膜负电荷改变、Perlecan蛋白及其降解酶Hpa含量变化,同时检测PI3K/AKT/mTOR信号通路相关蛋白以及自噬蛋白标志物的含量。结果:(1)成功构建了PE小鼠和HSPG2条件肾敲低小鼠模型。(2)相对于正常孕鼠,PE小鼠胶体铁染色显示负电荷基本消失,肾小球电荷屏障被破坏,蛋白免疫印迹结果显示PE小鼠肾小球中Perlecan蛋白表达(0.255±0.028)较正常孕鼠(0.509±0.022)显著降低;而Hpa表达(0.519±0.041)较正常孕鼠(0.260±0.063)显著升高(P均<0.05)。(3)与正常孕鼠相比,PE小鼠PI3K/AKT/mTOR信号通路相关蛋白PI3K(0.146±0.018 vs 0.448±0.048)、p-AKT(0.031±0.008 vs 0.286±0.030)和p-mTOR(0.179±0.029 vs0.364±0.025)表达显著下调,自噬相关标志物LC3-I/LC3-Ⅱ(0.546±0.060 vs 0.244±0.060)和Beclin-1(0.527±0.029 vs 0.191±0.044)表达显著升高,差异均有统计学意义(P均<0.05);PI3K/AKT/mTOR通路药理激活剂740 Y-P和MHY1485可以有效地弥补Perlecan敲低引起的自噬增加。结论:PE小鼠Perlecan蛋白下降除外引起肾小球电荷屏障损伤,还可能通过抑制PI3K/AKT/mTOR信号通路来促进细胞自噬引起肾脏血管内皮细胞损伤。
基金supported by the National Natural Science Foundation of China,No.30900300/C1002
文摘The present study observed sciatic nerve and gastrocnemius muscle changes in denervated rats using morphology methods, and assessed expression of perlecan, an extracellular matrix component, which is located at the skeletal muscle cell surface as acetylcholine esterase, as well as synaptophysin, a synaptic marker. Results showed degeneration and inflammation following transection of the sciatic nerve. In addition, the sciatic nerve-dominated skeletal muscle degenerated with mild inflammation, indicating that skeletal muscle atrophy primarily contributed to denervation-induced nutritional disturbances. With prolonged injury time （1-4 weeks post-injury）, perlecan expression gradually decreased and reached the lowest level at 4 weeks, but synaptophysin expression remained unchanged after denervation. Results suggested that perlecan expression was more sensitive to denervation and reflected regional extracellular matrix changes following denervation.
基金supported by NIH grants ( P30GM103333,R01AR054385)supported partially by a core access award through NIH NIGMS IDeA Program grant ( P20GM103446)
文摘Perlecan,a heparan sulfate proteoglycan,acts as a mechanical sensor for bone to detect external loading.Deficiency of perlecan increases the risk of osteoporosis in patients with Schwartz-Jampel Syndrome(SJS)and attenuates loading4nduced bone formation in perlecan deficient mice(Hypo).Considering that intracellular calcium[Ca2+]i is an ubiquitous messenger controlling numerous cellular processes including mechanotransduction,we hypothesized that perlecan deficiency impairs bone’s calcium signaling in response to loading.To test this,we performed real-time[Ca2+]i imaging on in situ osteocytes of adult murine tibiae under cyclic loading(8 N,Figure 1).Relative to wild type(WT),Hypo osteocytes showed decreases in the overall[Ca2+]i response rate(-58%),calcium peaks(-33%),cells with multiple peaks(-53%),peak magnitude(-6.8%),and recovery speed to baseline(-23%).RNA sequencing and pathway analysis of tibiae from mice subjected to one or seven days of unilateral loading demonstrated that perlecan deficiency significantly suppressed the calcium signaling,ECM-receptor interaction,and focal adhesion pathways following repetitive loading.Defects in the endoplasmic reticulum(ER)calcium cycling regulators such as Ryr1/ryanodine receptors and Atp2a1/Sercal calcium pumps were identified in Hypo bones.Taken together,impaired calcium signaling may contribute to bone’s reduced anabolic response to loading,underlying the osteoporosis risk for the SJS patients.
文摘Lens fibre differentiation is a life-long process related with lens transparency, and is particularly intense during development, being related with an FGF-2 antero-posterior gradient at the equator level as the main growth factor involved which has been related with the basal membrane of the lens anlagen known as “Lens capsule”. However the lens fibre differentiation induced by FGF2 depends, as in other biological systems, on the local bioavailability of FGF-2 regulated by their relationship with extracellular matrix molecules as Heparan Sulphate Proteoglycans. Here, we try to clarify how Perlecan (a heparan sulphate proteoglycan specific from basement membranes) is involved in lens fibre differentiation at earliest stages of eye development. Our results show that Perlecan, is a major component in the lens capsule during the earliest stages of lens development in chick embryos being present during lens plate induction, lens vesicle stage and the onset of lens fibre differentiation. In order to demonstrate a direct involvement of HSPG-Perlecan in lens fibre differentiation, we generate depleted lenses by HSPG-Perlecan synthesis disruption and specific enzymatic digestion. The HSPG-Perlecan depleted lens show a significant delay or abolition in the lens fibre differentiation which remains in an immature cells displaying DNA synthesis in the posterior epithelium and a decrease in FGF2 lens expression. These data support the hypothesis that lens capsule HSPG-Perlecan is a key molecule involved in lens fibre differentiation during development, probably by involvement in FGF-2 biodisponibility.
