The murine microglial cell line BV2 has neuroprotective effects, but is toxic to neurons by secret-ing inlfammatory cytokines, and is an important target in the treatment of nerve inlfammation and neurodegenerative di...The murine microglial cell line BV2 has neuroprotective effects, but is toxic to neurons by secret-ing inlfammatory cytokines, and is an important target in the treatment of nerve inlfammation and neurodegenerative diseases. In the present study, we observed the effects of transfecting three amyloid precursor-like protein 2 (APLP2) C-terminal fragments (CTFs; C57, C50 and C31) in the pEGFP-N1 vector on S100A9 expression in BV2 cells. Reverse transcription-PCR, western blot assay and immunocytochemistry revealed that S100A9 protein and mRNA expression was greater in BV2 cells after CTF transfection than after mock transfection with an empty vector. Furthermore, transfection of full-length APLP2-751 resulted in low levels of S100A9 protein ex-pression. Our results show that APLP2-CTFs upregulate S100A9 protein and mRNA expression in BV2 cells, and identify a novel pathway involved in neuronal injury and apoptosis, and repair and protection in Alzheimer’s disease.展开更多
Background:In plastic surgery,tissue expansion is widely used for repairing skin defects.However,low expansion efficiency and skin rupture caused by thin,expanded skin remain significant challenges in promoting skin r...Background:In plastic surgery,tissue expansion is widely used for repairing skin defects.However,low expansion efficiency and skin rupture caused by thin,expanded skin remain significant challenges in promoting skin regeneration during expansion.S100 calcium-binding protein A9(S100A9)is essential in promoting wound healing;however,its effects on skin regeneration during tissue expansion remain unclear.The aim of the present study was to explore the role of S100A9 in skin regeneration,particularly collagen production to investigate its importance in skin regeneration during tissue expansion.Methods:The expression and distribution of S100A9 and its receptors-toll-like receptor 4(TLR-4)and receptor for advanced glycation end products were studied in expanded skin.These character-istics were investigated in skin samples of rats and patients.Moreover,the expression of S100A9 was investigated in stretched keratinocytes in vitro.The effects of S100A9 on the proliferation and migration of skin fibroblasts were also observed.TAK-242 was used to inhibit the binding of S100A9 to TLR-4;the levels of collagen I(COL I),transforming growth factor beta(TGF-β),TLR-4 and phospho-extracellular signal-related kinase 1/2(p-ERK1/2)in fibroblasts were determined.Furthermore,fibroblasts were co-cultured with stretched S100A9-knockout keratinocytes by siRNA transfection and the levels of COL I,TGF-β,TLR-4 and p-ERK1/2 in fibroblasts were investigated.Additionally,the area of expanded skin,thickness of the dermis,and synthesis of COL I,TGF-β,TLR-4 and p-ERK1/2 were analysed to determine the effects of S100A9 on expanded skin.Results:Increased expression of S100A9 and TLR-4 was associated with decreased extracellular matrix(ECM)in the expanded dermis.Furthermore,S100A9 facilitated the proliferation and migration of human skin fibroblasts as well as the expression of COL I and TGF-βin fibroblasts via the TLR-4/ERK1/2 pathway.We found that mechanical stretch-induced S100A9 expression and secretion of keratinocytes stimulated COL I,TGF-β,TLR-4 and p-ERK1/2 expression in skin fibroblasts.Recombined S100A9 protein aided expanded skin regeneration and rescued dermal thinning in rats in vivo as well as increasing ECM deposition during expansion.Conclusions:These findings demonstrate that mechanical stretch promoted expanded skin regeneration by upregulating S100A9 expression.Our study laid the foundation for clinically improving tissue expansion using S100A9.展开更多
基金supported by the Natural Science Foundation of Technology Gallery in Jilin Province of China,No.2011-15237the National Natural Science Foundation of China,No.81160159
文摘The murine microglial cell line BV2 has neuroprotective effects, but is toxic to neurons by secret-ing inlfammatory cytokines, and is an important target in the treatment of nerve inlfammation and neurodegenerative diseases. In the present study, we observed the effects of transfecting three amyloid precursor-like protein 2 (APLP2) C-terminal fragments (CTFs; C57, C50 and C31) in the pEGFP-N1 vector on S100A9 expression in BV2 cells. Reverse transcription-PCR, western blot assay and immunocytochemistry revealed that S100A9 protein and mRNA expression was greater in BV2 cells after CTF transfection than after mock transfection with an empty vector. Furthermore, transfection of full-length APLP2-751 resulted in low levels of S100A9 protein ex-pression. Our results show that APLP2-CTFs upregulate S100A9 protein and mRNA expression in BV2 cells, and identify a novel pathway involved in neuronal injury and apoptosis, and repair and protection in Alzheimer’s disease.
基金supported by grants from the Natural Science Foundation of China(81971851 and 82172229)the Natural Science Foundation of Shaanxi Province(2022JM-600)the Foundation of Xijing Hospital Grants(XJZT21CM33).
文摘Background:In plastic surgery,tissue expansion is widely used for repairing skin defects.However,low expansion efficiency and skin rupture caused by thin,expanded skin remain significant challenges in promoting skin regeneration during expansion.S100 calcium-binding protein A9(S100A9)is essential in promoting wound healing;however,its effects on skin regeneration during tissue expansion remain unclear.The aim of the present study was to explore the role of S100A9 in skin regeneration,particularly collagen production to investigate its importance in skin regeneration during tissue expansion.Methods:The expression and distribution of S100A9 and its receptors-toll-like receptor 4(TLR-4)and receptor for advanced glycation end products were studied in expanded skin.These character-istics were investigated in skin samples of rats and patients.Moreover,the expression of S100A9 was investigated in stretched keratinocytes in vitro.The effects of S100A9 on the proliferation and migration of skin fibroblasts were also observed.TAK-242 was used to inhibit the binding of S100A9 to TLR-4;the levels of collagen I(COL I),transforming growth factor beta(TGF-β),TLR-4 and phospho-extracellular signal-related kinase 1/2(p-ERK1/2)in fibroblasts were determined.Furthermore,fibroblasts were co-cultured with stretched S100A9-knockout keratinocytes by siRNA transfection and the levels of COL I,TGF-β,TLR-4 and p-ERK1/2 in fibroblasts were investigated.Additionally,the area of expanded skin,thickness of the dermis,and synthesis of COL I,TGF-β,TLR-4 and p-ERK1/2 were analysed to determine the effects of S100A9 on expanded skin.Results:Increased expression of S100A9 and TLR-4 was associated with decreased extracellular matrix(ECM)in the expanded dermis.Furthermore,S100A9 facilitated the proliferation and migration of human skin fibroblasts as well as the expression of COL I and TGF-βin fibroblasts via the TLR-4/ERK1/2 pathway.We found that mechanical stretch-induced S100A9 expression and secretion of keratinocytes stimulated COL I,TGF-β,TLR-4 and p-ERK1/2 expression in skin fibroblasts.Recombined S100A9 protein aided expanded skin regeneration and rescued dermal thinning in rats in vivo as well as increasing ECM deposition during expansion.Conclusions:These findings demonstrate that mechanical stretch promoted expanded skin regeneration by upregulating S100A9 expression.Our study laid the foundation for clinically improving tissue expansion using S100A9.