title: Cofilin1 is involved in hypertension-induced renal damage via the regulation of NF-κB in renal tubular epithelial cells.
abstract: BACKGROUND
  Inflammation mediated by nuclear factor-κB (NF-κB) plays a critical role in the pathogenesis of hypertensive nephropathy (HN). Cytoskeletal remodelling is necessary for the activation of NF-κB. An actin-binding protein, cofilin-1 promotes dynamic alterations to the cytoskeleton by severing actin filaments. However, whether cofilin1 modulates NF-κB activity via cytoskeletal remodelling in the setting of hypertensive renal damage and what mechanisms underlie this phenomenon, remain unknown.
  
  
  METHODS
  Twenty-one-week old spontaneously hypertensive rats (SHRs) were treated with an antioxidant (100 or 250 mg kg(-1) day(-1)), grape seed proanthocyanidins extract (GSPE), for 22 weeks. Twenty-four-hour urinary protein, serum creatinine and urea nitrogen levels were measured. Haematoxylin and eosin (HE) staining was performed, and the expression levels of renal cortex cofilin1, monocyte chemotactic protein 1 (MCP1), interleukin-1β (IL1β) and NF-κB were evaluated via either Western blotting or immunohistochemistry. In vitro, human proximal renal tubular epithelial cells (HK-2 cells) were pre-incubated either with or without GSPE and subsequently treated with angiotensinII (AngII). Furthermore, a lentiviral shRNA-vector was utilized to knockdown cofilin1 expression in the HK-2 cells, which were stimulated with AngII. Actin filaments, NF-κB activity and several downstream inflammatory factors, including MCP1 and IL-1β, were investigated.
  
  
  RESULTS
  In addition to elevated blood pressure and 24 h urinary protein levels, NF-κB activity and the expression levels of MCP1 and IL-1β were significantly increased, resulting in tubulointerstitial inflammatory infiltration in SHRs. The phosphorylation (inactivation) of cofilin1 was increased in the kidneys of the SHRs. In vitro, AngII stimulation resulted in the phosphorylation of cofilin1, the formation of actin stress fibres and nuclear translocation of NF-κB p65 in the HK2 cells. Both GSPE pretreatment and the shRNA knockdown of cofilin1 inhibited Rel/p65 nuclear translocation, as well as the expression of both MCP-1 and IL-1β in the AngII-induced HK2 cells.
  
  
  CONCLUSIONS
  These results demonstrate that cofilin1 is involved in hypertensive nephropathy by modulating the nuclear translocation of NF-κB and the expression of its downstream inflammatory factors in renal tubular epithelial cells.
authors.affiliation: Department of Geriatric Cardiology, Qilu Hospital of Shandong University, 107 Wenhua Xi Rd, 250012, Jinan, People's Republic of China. wangquanzhen1986@163.com.
authors.forename: Quan-Zhen
authors.initials: QZ
authors.lastname: Wang
authors.affiliation: Department of Geriatric Cardiology, Qilu Hospital of Shandong University, 107 Wenhua Xi Rd, 250012, Jinan, People's Republic of China. gaohaiqing@sdu.edu.cn.
authors.forename: Hai-Qing
authors.initials: HQ
authors.lastname: Gao
authors.affiliation: Department of Geriatric Cardiology, Qianfuoshan Hospital of Shandong Province, 16766 Jingshi Rd, 250000, Jinan, People's Republic of China. liangying2970@sina.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Department of Geriatric Cardiology, Qilu Hospital of Shandong University, 107 Wenhua Xi Rd, 250012, Jinan, People's Republic of China. junermiaomiao@163.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Geriatric Cardiology, Qilu Hospital of Shandong University, 107 Wenhua Xi Rd, 250012, Jinan, People's Republic of China. jian19880907@126.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Geriatric Cardiology, Qilu Hospital of Shandong University, 107 Wenhua Xi Rd, 250012, Jinan, People's Republic of China. drqiujie@163.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Qiu
mesh_terms: D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000737:chemistry; D018932:Chemokine CCL2 / Q000378:metabolism; D051338:Cofilin 1 / Q000378:metabolism*; D003404:Creatinine / Q000097:blood; D003599:Cytoskeleton / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism*; D005786:Gene Expression Regulation; D056604:Grape Seed Extract / Q000737:chemistry; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007249:Inflammation; D053583:Interleukin-1beta / Q000378:metabolism; D007684:Kidney Tubules / Q000378:metabolism*; D008297:Male; D052002:NF-kappa B p50 Subunit / Q000378:metabolism*; D009584:Nitrogen / Q000032:analysis; D044945:Proanthocyanidins / Q000737:chemistry; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D051437:Renal Insufficiency / Q000378:metabolism*; D014508:Urea / Q000032:analysis
chemical_list: D000975:Antioxidants; C495810:CFL1 protein, human; C495812:Cfl1 protein, rat; D018932:Chemokine CCL2; D051338:Cofilin 1; D056604:Grape Seed Extract; C511402:Grape Seed Proanthocyanidins; C000594089:IL1B protein, rat; D053583:Interleukin-1beta; D052002:NF-kappa B p50 Subunit; C489548:NFKB1 protein, human; D044945:Proanthocyanidins; D034741:RNA, Small Interfering; D000804:Angiotensin II; D014508:Urea; D003404:Creatinine; D009584:Nitrogen