BACKGROUND:Bone morphogenetic protein 7 is mainly synthesized in the kidney and is expressed at different stages of kidney development,but the spatiotemporal distribution of its expression and its relationship with kidney development have not been systematically reported.OBJECTIVE:To observe the expression of bone morphogenetic protein 7 in mice kidneys during different developmental stages and to explore its potential relationship with kidney development.METHODS:Immunohistochemical techniques combined with stereological methods and western blot analysis were used to observe and analyze the expression of bone morphogenetic protein 7 in mouse kidney tissues at embryonic days(E)12,14,16,18,and neonatal days(N)1,3,7,14,24,40,and 70.RESULTS AND CONCLUSION:(1)The results of immunohistochemistry showed that bone morphogenetic protein 7 was mainly expressed in the nephrogenic zone and immature renal corpuscles during the early stage of kidney development.Subsequently,it was located in mature renal corpuscles and the surrounding distal convoluted tubules,and the expression range gradually increased.After N40 days,bone morphogenetic protein 7 positively expressed in the renal interstitium.(2)Stereology and western blot results showed that the expression level of bone morphogenetic protein 7 gradually decreased with the development of the kidney,reached the lowest level at N7 days,and then slowly increased.To conclude,during the process of kidney development,the expression of bone morphogenetic protein 7 has significant spatiotemporal specificity,and it is hypothesized that it may be related to the development and maturation of renal corpuscles and distal convoluted tubules.

BACKGROUND:Bone morphogenetic protein 7 is mainly synthesized in the kidney and is expressed at different stages of kidney development,but the spatiotemporal distribution of its expression and its relationship with kidney development have not been systematically reported.OBJECTIVE:To observe the expression of bone morphogenetic protein 7 in mice kidneys during different developmental stages and to explore its potential relationship with kidney development.METHODS:Immunohistochemical techniques combined with stereological methods and western blot analysis were used to observe and analyze the expression of bone morphogenetic protein 7 in mouse kidney tissues at embryonic days(E)12,14,16,18,and neonatal days(N)1,3,7,14,24,40,and 70.RESULTS AND CONCLUSION:(1)The results of immunohistochemistry showed that bone morphogenetic protein 7 was mainly expressed in the nephrogenic zone and immature renal corpuscles during the early stage of kidney development.Subsequently,it was located in mature renal corpuscles and the surrounding distal convoluted tubules,and the expression range gradually increased.After N40 days,bone morphogenetic protein 7 positively expressed in the renal interstitium.(2)Stereology and western blot results showed that the expression level of bone morphogenetic protein 7 gradually decreased with the development of the kidney,reached the lowest level at N7 days,and then slowly increased.To conclude,during the process of kidney development,the expression of bone morphogenetic protein 7 has significant spatiotemporal specificity,and it is hypothesized that it may be related to the development and maturation of renal corpuscles and distal convoluted tubules.

BACKGROUND:The temporal and spatial expression of fibroblast growth factor receptors 1 and 2 remains a controversial issue during kidney development,so the relationship between them and kidney development remains unclear. OBJECTIVE:To observe the dynamic expression of fibroblast growth factor receptors 1 and 2 during kidney development of mice,and to investigate the relationship between them and kidney development. METHODS:The kidneys of fetal mice[embryotic days(E)12,14,16,and 18]and neonatal mice[neonatal days(N)1,3,7,14,24,and 40]were selected to examine the temporal and spatial expression of fibroblast growth factor receptors 1 and 2 by immunohistochemistry method in kidney tissues,and quantitative analysis was performed using western blot assay. RESULTS AND CONCLUSION:(1)Immunohistochemistry showed that fibroblast growth factor receptor 1 was mainly localized in metanephric tissue surrounding the tip of the ureteral bud at E12.Subsequently,fibroblast growth factor receptor 1 was expressed in immature renal corpuscles at various stages,some distal convoluted tubules and capillary loops.The positive site was mainly concentrated in the generative region.Fibroblast growth factor receptor 2 was initially expressed in both ureteral buds and metanephric tissue.Fibroblast growth factor receptor 2 was localized in immature renal corpuscles,distal tubules,collecting ducts and thin segments of medullary loops with kidney development.However,the expression of renal corpuscles was weak.(2)Stereology and western blot assay showed that the expression of fibroblast growth factor receptor 1 was high before birth and gradually decreased after birth,while the expression was very low after N7 day.The expression level of fibroblast growth factor receptor 2 increased gradually with the kidney development and tended to be stable after N7 day.(3)The results exhibit that fibroblast growth factor receptors 1 and 2 are expressed spatially and temporally during kidney development.It is speculated that fibroblast growth factor receptors 1 and 2 may influence nephron development and maturation,and fibroblast growth factor receptor 2 is critical during the formation of ureteral buds and morphology.

Objective To observe the expression of aquaporin-7 (AQP-7)during the development of renal tubules of mice,and investigate the relationships between AQP-7 and renal tubule development.Methods Kidneys were selected from mice at embryonic days(E)12,14,17,and 18 and postnatal days(P)1,3,7,14,24,40 and 70.The expression of AQP-7 was observed by immunohistochemical(IHC)method in renal tubules.The surface area density values of AQP-7 positive expression were measured by stereological method while the content variation of AQP-7 in the renal tissue of mice was examined by Western blot.Results IHC analysis showed that AQP-7 was expressed in developing renal tubules at the proximal tubule at E14 day,localized along the brush border of the proximal straight tubules (S3 segment)where the cortex and outer medullalie after P14 d,but AQP-7 was not observed in the nephrogenic zone or inner medulla.The results of stereology discovered that the surface area density values of AQR-7 had increased gradually in the apical of renal tubule and reached the maximum at P24 d and then remained stable with the growth of mice.Western blot indicated that AQP-7 expression in kidneys had reached the peak at P24 d and remained stable.Conclusion The expressions of AQP-7 in the developing renal tubules of mice show a chronological and spatial sequence,which plays an important role in water and glycerol balance of mouse kidneys at the late stage of development.