scholarly journals Tubule-Specific Deletion of LincRNA-p21 Ameliorates Lipotoxic Kidney Injury

Author(s):  
Bin Li ◽  
Joseph C.K. Leung ◽  
Loretta Y.Y. Chan ◽  
Hong-Yu Li ◽  
Wai-Han Yiu ◽  
...  
2016 ◽  
Vol 311 (5) ◽  
pp. F1005-F1014 ◽  
Author(s):  
Linlin Guo ◽  
Hannah Heejung Lee ◽  
María de las Mercedes Noriega ◽  
Hans J. Paust ◽  
Gunther Zahner ◽  
...  

Acute kidney injury (AKI) is associated with poor patient outcome and a global burden for end-stage renal disease. Ischemia-reperfusion injury (IRI) is one of the major causes of AKI, and experimental work has revealed many details of the inflammatory response in the kidney, such as activation of the NF-κB pathway. Here, we investigated whether deletion of the NF-κB kinases IKK2 or NEMO in lymphocytes or systemic inhibition of IKK2 would cause different kidney inflammatory responses after IRI induction. Serum creatinine, blood urea nitrogen (BUN) level, and renal tubular injury score were significantly increased in CD4creIKK2f/f (CD4xIKK2Δ) and CD4creNEMOf/f (CD4xNEMOΔ) mice compared with CD4cre mice after IRI induction. The frequency of Th17 cells infiltrating the kidneys of CD4xIKK2Δ or CD4xNEMOΔ mice was also significantly increased at all time points. CCL20, an important chemokine in Th17 cell recruitment, was significantly increased at early time points after the induction of IRI. IL-1β, TNF-α, and CCL2 were also significantly increased in different patterns. A specific IKK2 inhibitor, KINK-1, reduced BUN and serum creatinine compared with nontreated mice after IRI induction, but the frequency of kidney Th17 cells was also significantly increased. In conclusion, although systemic IKK2 inhibition improved kidney function, lymphocyte-specific deletion of IKK2 or NEMO aggravated kidney injury after IRI, and, in both conditions, the percentage of Th17 cells was increased. Our findings demonstrate the critical role of the NF-κB pathway in Th17 activation, which advises caution when using systemic IKK2 inhibitors in patients with kidney injury, since they might impair the T cell response and aggravate renal disease.


2021 ◽  
pp. ASN.2020030263
Author(s):  
Katsuyuki Matsushita ◽  
Kiyoshi Mori ◽  
Turgay Saritas ◽  
Mahaba Eiwaz ◽  
Yoshio Funahashi ◽  
...  

Background Rhabdomyolysis, the destruction of skeletal muscle, is a significant cause of acute kidney injury (AKI) and death in the context of natural disaster and armed conflict. Rhabdomyolysis may also initiate chronic kidney disease (CKD). Development of specific pharmacologic therapy is desirable because supportive care is nearly impossible in austere environments. Myoglobin, the principal cause of rhabdomyolysis-related AKI, undergoes megalin-mediated endocytosis in proximal tubule cells, a process that specifically injures these cells. Methods To investigate whether megalin is protective in a mouse model of rhabdomyolysis-induced AKI, we used male C57BL/6 mice and mice (14-32 weeks old) with proximal tubule-specific deletion of megalin. We used a well-characterized rhabdomyolysis model, injection of 50% glycerol in normal saline preceded by water deprivation. Results Inducible proximal tubule-specific deletion of megalin was highly protective in this mouse model of rhabdomyolysis-induced AKI. The megalin knockout mice demonstrated preserved glomerular filtration rate (GFR), reduced proximal tubule injury (as indicated by kidney injury molecule-1), and reduced renal apoptosis 24 hours after injury. These effects were accompanied by increased urinary myoglobin clearance. Unlike littermate controls, the megalin-deficient mice also did not develop progressive GFR decline and persistent new proteinuria. Administration of the pharmacologic megalin inhibitor cilastatin to wild-type mice recapitulated the renoprotective effects of megalin deletion. This cilastatin-mediated renoprotective effect was dependent on megalin. Cilastatin administration caused selective proteinuria and inhibition of tubular myoglobin uptake similar to that caused by megalin deletion. Conclusions We conclude that megalin plays a critical role in rhabdomyolysis-induced AKI, and megalin interference and inhibition ameliorate rhabdomyolysis-induced AKI. Further investigation of megalin inhibition may inform translational investigation of a novel potential therapy.


2018 ◽  
Vol 315 (1) ◽  
pp. F186-F198 ◽  
Author(s):  
Andrey V. Cybulsky ◽  
Joan Papillon ◽  
Julie Guillemette ◽  
Natalya Belkina ◽  
Genaro Patino-Lopez ◽  
...  

SLK is essential for embryonic development and may play a key role in wound healing, tumor growth, and metastasis. Expression and activation of SLK are increased in kidney development and during recovery from ischemic acute kidney injury. Overexpression of SLK in glomerular epithelial cells/podocytes in vivo induces injury and proteinuria. Conversely, reduced SLK expression leads to abnormalities in cell adhesion, spreading, and motility. Tight regulation of SLK expression thus may be critical for normal renal structure and function. We produced podocyte-specific SLK-knockout mice to address the functional role of SLK in podocytes. Mice with podocyte-specific deletion of SLK showed reduced glomerular SLK expression and activity compared with control. Podocyte-specific deletion of SLK resulted in albuminuria at 4–5 mo of age in male mice and 8–9 mo in female mice, which persisted for up to 13 mo. At 11–12 mo, knockout mice showed ultrastructural changes, including focal foot process effacement and microvillous transformation of podocyte plasma membranes. Mean foot process width was approximately twofold greater in knockout mice compared with control. Podocyte number was reduced by 35% in knockout mice compared with control, and expression of nephrin, synaptopodin, and podocalyxin was reduced in knockout mice by 20–30%. In summary, podocyte-specific deletion of SLK leads to albuminuria, loss of podocytes, and morphological evidence of podocyte injury. Thus, SLK is essential to the maintenance of podocyte integrity as mice age.


Author(s):  
Patricia Klemm ◽  
Anandhi Rajendiran ◽  
Athanassios Fragoulis ◽  
Christoph Wruck ◽  
Angela Schippers ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document