Exaggerated renal fibrosis in P2X4 receptor-deficient mice following unilateral ureteric obstruction

Abstract Background and Aims Kruppel-like factors (KLFs) comprise a family of zinc-finger transcription factors that play a critical role in development, proliferation, and regeneration following injury. There are over 17 members of this family; recent studies have shown that KLF family members regulate podocyte differentiation, preservation of the glomerular filtration barrier, and regulation of mitochondrial function. However, a role for KLF11 in renal pathophysiology has not been previously established. Method Wild-type (WT) and KLF11 knockout (KO) mice were subjected to unilateral ureteric obstruction (UUO), a well-established model of renal inflammation and fibrosis; controls included mice subjected to manipulation of the ureter without ligation. Kidneys were harvested after 9 days (n=8 animals per group). Semiquantitative histopathologic analysis of renal atrophy, fibrosis, and inflammation was performed in a blinded fashion. Gene expression analysis was performed on renal cortex employing the Pathway Detect RNA array and RNASeq. Results In UUO, renal atrophy was more severe in KLF11 KO mice than WT mice (p<0.001). Deposition of collagen, as assessed by quantitative analysis of Sirus Red stained sections, was greater in KLF11 KO mice, compared to WT mice subjected to UUO; COL3A1 expression was also increased (p<0.05). Atrophy was associated with an increase in F4/80+ (p<0.01) and CD206+ macrophages (p<0.05), but not CD3+ T cells in KLF11 KO vs. WT mice. Induction of CC chemokines, including CCL2, CCL5, CCL7, CCL12, and CCL2 as well as CCR2 was significantly higher in KLF11 KO versus WT mice subjected to UUO (all p<0.001). Expression of NF-kB (p<0.01) and TNF alpha (p<0.01), but not IL-1 beta, IL-6, or IL-10 were significantly higher in KLF11 KO than WT mice with UUO. Expression of TGF-beta 1, Smad2, and Smad3 were also higher in KLF11 KO mice than WT mice with UUO (p<0.05). Conclusion Renal injury in UUO is exacerbated in KLF11 KO mice, compared to WT mice. Injury is associated with increased macrophage influx and production of pro-inflammatory chemokines. Future studies will determine how KLF11 deficiency directs transcription of pro-inflammatory and pro-fibrotic genes.

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Deficiency of the purinergic receptor P2X4 limits atherosclerosis in mice

European Heart Journal ◽

10.1093/ehjci/ehaa946.3795 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

S Koenig ◽

A Peikert ◽

J Merz ◽

K Rofa ◽

I Schaefer ◽

...

Keyword(s):

Atherosclerotic Plaque ◽

Aortic Root ◽

Peripheral Blood ◽

Leukocyte Recruitment ◽

Funding Source ◽

P2x4 Receptor ◽

Atherosclerotic Lesions ◽

Anti Inflammatory ◽

Deficient Mice ◽

Research Grant

Abstract Introduction Extracellular nucleotides like ATP promote inflammation as danger signals in various chronic diseases via purinergic receptors. In our previous work we identified P2X4 expression in murine atherosclerotic lesions. Therefore, we hypothesized a contribution of the ATP-P2X4 axis to vascular inflammation in atherosclerosis. Methods To investigate the functional role of P2X4 in atherogenesis, wild-type LDL-receptor deficient mice (LDLR−/−) and P2X4-deficient LDLR−/− mice (P2X4−/−LDLR−/−) were fed a high cholesterol diet for 16 weeks. Plaque progression in aortic arches was monitored by echography at intervals of 4 weeks, and leukocyte subsets in blood samples were analysed by flow cytometry. Atherosclerotic lesions were then assessed histologically in aortic root, arch, and abdominal aorta. In order to assess leukocyte recruitment, intravital microscopy was performed after injection of ATP in P2X4−/− or wildtype mice (WT). Regarding transferability to human disease, atherosclerotic plaque from carotid endarterectomy has been stained immunohistochemically for P2X4-receptor expression. Results After 16 weeks, P2X4-deficient mice showed significantly reduced atherosclerotic lesions in the aortic root (n=40, LDLR−/−: 0.47 mm2, P2X4−/−LDLR−/−: 0.39 mm2, p=0.04). Ly6C- monocyte count in peripheral blood was higher in P2X4−/−LDLR−/− (n=32, LDLR−/−: 241/μl, P2X4−/−LDLR−/−: 542/μl, p=0.0088), shifting the balance to a more anti-inflammatory subset. Memory-cell generation of CD4-T-cells is significantly higher in knockout-mice, suggesting an involvement of T-helper cells (n=25, LDLR−/−: 27%, P2X4−/−LDLR−/−: 46%, p=0.0003). Peritoneally injected ATP induced leukocyte rolling in WT, but not in P2X4-deficient mice. In human carotid arteries, atherosclerotic plaque shows higher staining for P2X4−/− receptor than not diseased areas. Conclusion P2X4-deficiency enhances anti-inflammatory leukocytes in peripheral blood and reduces atherosclerosis. Therefore, blocking the ATP-P2X4 axis may prevent leukocyte recruitment to atherosclerotic lesions and could present a potential new target for anti-atherogenic therapy. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported by a research grant of the German Research Foundation (DFG) to Peter Stachon. Sebastian König was supported by a research grant of the German Cardiac Society (DGK)

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SAT-177 KLF11 DEFICIENCY EXACERBATES RENAL INJURY IN EXPERIMENTAL UNILATERAL URETERIC OBSTRUCTION

Kidney International Reports ◽

10.1016/j.ekir.2020.02.189 ◽

2020 ◽

Vol 5 (3) ◽

pp. S75-S76

Author(s):

J. Grande ◽

M. Osman ◽

S. De Lorenzo ◽

A. Vrieze ◽

A. Osman ◽

...

Keyword(s):

Renal Injury ◽

Ureteric Obstruction ◽

Unilateral Ureteric Obstruction

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Increased E-cadherin expression in the ligated kidney following unilateral ureteric obstruction

Kidney International ◽

10.1038/ki.2008.482 ◽

2009 ◽

Vol 75 (2) ◽

pp. 205-213 ◽

Cited By ~ 22

Author(s):

Neil G. Docherty ◽

Isabel Fuentes Calvo ◽

Mark R. Quinlan ◽

Fernando Pérez-Barriocanal ◽

Barry B. McGuire ◽

...

Keyword(s):

Ureteric Obstruction ◽

Unilateral Ureteric Obstruction ◽

E Cadherin

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Evidence that inhibition of tubular cell apoptosis protects against renal damage and development of fibrosis following ureteric obstruction

AJP Renal Physiology ◽

10.1152/ajprenal.00045.2005 ◽

2006 ◽

Vol 290 (1) ◽

pp. F4-F13 ◽

Cited By ~ 111

Author(s):

Neil G. Docherty ◽

Orfhlaith E. O'Sullivan ◽

Declan A. Healy ◽

John M. Fitzpatrick ◽

R. William G. Watson

Keyword(s):

Cell Death ◽

Renal Function ◽

Renal Damage ◽

Obstructive Uropathy ◽

Pressure Control ◽

Organ Damage ◽

Special Focus ◽

Ureteric Obstruction ◽

Unilateral Ureteric Obstruction

Ureteric obstruction is frequently encountered in primary care urology and can lead to damage to the ipsilateral kidney. Relief of all types of obstruction generally leads to the normalization of any deterioration in renal function noted at diagnosis. However, some evidence from animal models suggests that obstruction can cause progressive deleterious effects on renal function and blood pressure control, especially in the presence of preexisting pathologies such as essential hypertension. The last 10 years have seen a proliferation of studies in rodents wherein complete unilateral ureteric obstruction has been used as a model of renal fibrosis. However, the relevance of the findings to human obstructive uropathy has, in many cases, not been the primary aim. In this review, we outline the major events linking damage to the renal parenchyma and cell death to the evolution of fibrosis following obstruction. Special focus is given to the role of apoptosis as a major cause of cell death during and post-complete ureteric obstruction. Several interventions that reduce tubular apoptosis are discussed in terms of their ability to prevent subsequent progression to end-organ damage and fibrosis.

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