[en] Background and Aims:
Whole-body irradiation has been suggested to induce renal ischemic preconditioning (RIP) in rodent models, possibly via neo-angiogenesis. First, we comprehensively investigate the pathways involved in kidney-centered irradiation. Next, we assess the functional and structural impact of kidney-centered irradiation applied before ischemia/reperfusion (I/R) injury. Finally, we test whether Sunitinib-mediated inhibition of the neo-angiogenesis prevents irradiation-associated RIP.
Method:
Experiment 1:
Unilateral irradiation of the left kidney (8.56 Gy) was performed in male 10-week-old wild-type C57bl/6 mice (n=10). One month later, total kidney RNAs were extracted from irradiated and control (n=5) mice for comparative high-throughput RNA-Seq (using BaseSpace Sequence Hub Illumina). Functional enrichment analysis was performed using Database for Annotation, Visualization and Integrated Discovery (DAVID).
Experiment 2:
Two x-ray beams (225Kv, 13mA) specifically targeted both kidneys for a total dose of 8.56Gy. Fourteen days later, the right kidneys were removed and harvested, and the left kidneys undergo 30-minute ischemia followed by 48-hour reperfusion (n=8).
Experiment 3:
Following the same protocol of renal I/R, 3 groups of male 10-week-old wild-type C57bl/6 mice were compared (n=8 animals per group):
1/ irradiation
2/ irradiation and gavage with Sunitinib for 14days
3/ control group without irradiation or gavage.
All groups undergo an I/R after treatments.
Results:
Experiment 1:
Comparative transcriptomics showed a significant up-regulation of various signaling pathways, including angiogenesis (HMOX1) and stress response (HSPA1A, HSPA1B). Expressions of angiogenesis markers (CD31, TGFb1, HMOX1) shows an increase at both mRNA (real-time qPCR) and protein (immune-staining) levels in irradiated kidneys compared to controls (p<0.01).
Experiment 2:
Following I/R, the blood urea nitrogen (BUN) and serum creatinine (SCr) levels were significantly lower in the irradiated animals compared to controls: (BUN: 86.2±6.8 vs. 454.5±27.2mg/dl; SCr: 0.1±0.01 vs. 1.7±0.2mg/dl, p<0.01). The renal infiltration by CD11b-positive cells (187±32 vs. 477±20/mm²) and F4-80 macrophages (110±22 vs. 212±25/mm²) was significantly reduced in the irradiated group. The real-time qPCR mRNA levels of the angiogenic markers, TGFb1 and CD31, were significantly increased in the irradiated group compared to controls (p<0,01). The CD31-immunostaining was increased in irradiated group compared to controls (p<0.01).
Experiment 3: Following I/R, the serum levels of BUN and SCr were lower in pre-irradiated animals compared to controls (BUN: 106.1±33.6 vs. 352.2±54.3mg/dl; SCr: 0.3±0.13 vs. 1±0.2mg/dl), and to the irradiated-exposed group to Sunitinib (BUN: 106.1±33.6 vs. 408.4±54.9mg/dl; SCr: 0.3±0.12 vs. 1.5±0.3mg/dl; p<0.01). No difference observed between the irradiated-exposed mice to Sunitnib and the controls.
Conclusion:
Renal irradiation induces the activation of signaling pathways involved in angiogenesis in mice. Renal irradiation causes ischemic preconditioning, with preserved renal function and attenuated inflammation post I/R. Exposure to the anti-angiogenic drug Sunitinib post-irradiation prevents the irradiation-induced nephroprotection against I/R.
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.