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Cyclophosphamide (CP) is one of the most extensively used antineoplastic drug, but the nephrotoxicity caused by this drug is a major limiting factor for its use. Nerolidol (NERO) is a natural bioactive compound with diverse pharmacological actions. In Vitro and in vivo study was performed using HK-2 renal cells and Swiss Albino mice. Cell lines and animals were treated with NERO 25 and 50 µM + 30 µM CP (in vitro), 200 and 400 mg/kg, p.o. NERO from day 1 to day 15 + 200 mg/kg, i.p. CP on day 17 as single intraperitoneal injection (in vivo). The makers of oxidative stress, renal-specific injury markers, inflammation, apoptosis, fibrosis, and histopathological changes were studied. The study's outcome showed a significant reduction in the level of malonaldehyde and interleukin-6 (p < 0.01), tumor necrosis factor-α, IL-1β (p < 0.001), and an increase in the superoxide dismutase, catalase, glutathione and interleukin-10 level (p < 0.01), in the in vivo study when treated with NERO 400 and compared with CP 200. In Vitro study showed reduced expression of nuclear factor kappa light chain enhancer of activated B cells, cleaved caspase-3, kidney injury molecule-1 and transforming growth factor-β-1 (p < 0.001), when treated with NERO 50 µM whereas NERO 25 µM only reduced the level of cleaved caspase-3 (p < 0.05) when compared with 30 µM. NERO 400 also reduced uric acid (p < 0.05), urea (p < 0.01), blood urea nitrogen, and serum creatinine levels (p < 0.001) and increased the level of blood-urea-nitrogen/creatinine ratio (p < 0.001). Additionally, the level of fibrosis-specific markers such as transforming growth factor-β1, hyaluronic acid (p < 0.01), 4-hydroxyproline, a collagen-rich area in Masson's' trichome stain, and Smad3 expression was also significantly reduced (p < 0.001). Furthermore, the outcome of multiple renal staining showed structural reversal aberrations, reduction of the thick basement membrane, and glycogen level toward normal when treated with NERO 400. Thus, the study showed a novel mechanistic modality of NERO against cyclophosphamide-induced renal toxicity. The outcome of this study can be considered a step closer to the development of an adjuvant to mitigate cyclophosphamide-induced renal toxicity among patients treated with cyclophosphamide. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) is prevalent worldwide and is associated with significant co-morbidities including cardiovascular disease (CVD). Traditionally, the subtotal nephrectomy (remnant kidney) experimental model has been performed in rats to model progressive renal disease. The model experimentally mimics CKD by reducing nephron number, resulting in renal insufficiency. Presently, there is a lack of translation of pre-clinical findings into successful clinical results. The pre-clinical nephrology field would benefit from reproducible progressive renal disease models in mice in order to avail of more widely available transgenics and experimental tools to dissect mechanisms of disease. Here we evaluate if a simplified single step subtotal nephrectomy (STNx) model performed in the 129S2/SV mouse can recapitulate the renal and cardiac changes observed in patients with CKD in a reproducible and robust way. The single step STNx surgery was well-tolerated and resulted in clinically relevant outcomes including hypertension, increased urinary albumin:creatinine ratio, and significantly increased serum creatinine, phosphate and urea. STNx mice developed significant left ventricular hypertrophy without reduced ejection fraction or cardiac fibrosis. Analysis of intra-renal inflammation revealed persistent recruitment of Ly6Chi monocytes transitioning to pro-fibrotic inflammatory macrophages in STNx kidneys. Unlike 129S2/SV mice, C57BL/6 mice exhibited renal fibrosis without proteinuria, renal dysfunction, or cardiac pathology. Therefore, the 129S2/SV genetic background is susceptible to induction of progressive proteinuric renal disease and cardiac hypertrophy using our refined, single-step flank STNx method. This reproducible model could be used to study the systemic pathophysiological changes induced by CKD in the kidney and the heart, intra-renal inflammation and for testing new therapies for CKD.

Chronic kidney disease (CKD) is prevalent worldwide and is associated with significant co-morbidities including cardiovascular disease (CVD). Traditionally, the subtotal nephrectomy (remnant kidney) experimental model has been performed in rats to model progressive renal disease. The model experimentally mimics CKD by reducing nephron number, resulting in renal insufficiency. Presently, there is a lack of translation of pre-clinical findings into successful clinical results. The pre-clinical nephrology field would benefit from reproducible progressive renal disease models in mice in order to avail of more widely available transgenics and experimental tools to dissect mechanisms of disease. Here we evaluate if a simplified single step subtotal nephrectomy (STNx) model performed in the 129S2/SV mouse can recapitulate the renal and cardiac changes observed in patients with CKD in a reproducible and robust way. The single step STNx surgery was well-tolerated and resulted in clinically relevant outcomes including hypertension, increased urinary albumin:creatinine ratio, and significantly increased serum creatinine, phosphate and urea. STNx mice developed significant left ventricular hypertrophy without reduced ejection fraction or cardiac fibrosis. Analysis of intra-renal inflammation revealed persistent recruitment of Ly6C hi monocytes transitioning to pro-fibrotic inflammatory macrophages in STNx kidneys. Unlike 129S2/SV mice, C57BL/6 mice exhibited renal fibrosis without proteinuria, renal dysfunction, or cardiac pathology. Therefore, the 129S2/SV genetic background is susceptible to induction of progressive proteinuric renal disease and cardiac hypertrophy using our refined, single-step flank STNx method. This reproducible model could be used to study the systemic pathophysiological changes induced by CKD in the kidney and the heart, intra-renal inflammation and for testing new therapies for CKD. [ABSTRACT FROM AUTHOR]

Renal fibrosis and inflammation are common underlying processes of progressive kidney diseases. Elongator protein 2 (Elp2), identical to signal transducer and activator of transcription-3 (STAT-3)-interacting protein-1 (Stip1), is a component of the Elongator complex that regulates RNA polymerase II. Elp2 regulates STAT-3 activation to control various cellular processes. The mechanisms of Elp2 prevention in renal interstitial fibrosis and inflammation remain unknown. In the study, Elp2 transgenic knockout (KO) and wild type (WT) mice were employed to investigate the effects of Elp2 on renal fibrosis and inflammation development after unilateral ureter obstruction (UUO) surgery. The results indicted that Elp2 was significantly expressed in renal tissues of WT/UUO mice. Elp2-KO mice exhibited attenuated histological changes of kidney, as well as collagen and fibrosis accumulation. Lower expressions of transforming growth factor (TGF)-β1, α-smooth muscle actin (α-SMA), fibronectin, vimentin, and phospho-Smad2/3 were observed in kidney of Elp2-KO mice than that of WT mice after UUO. Elp2-KO mice showed less inflammation, as evidenced by the decrease of circulating or renal pro-inflammatory cytokines, as well as the reduction of phospho-nuclear factor (NF)-κB. Additionally, Elp2-KO apparently led to a decrease in phospho-STAT3 in kidney of UUO mice. In vitro, we found that TGF-β1- and LPS-induced fibrosis and inflammation were abrogated by Elp2 knockdown, which were intriguingly abolished by activating STAT3 phosphorylation using its activator of colivelin (Col). Together, our findings supplied that Elp2 might be a potential therapeutic target to prevent the progression of renal fibrosis and inflammation. [ABSTRACT FROM AUTHOR]

Although Smad3 is a key mediator for fibrosis, its functional role and mechanisms in hypertensive nephropathy remain largely unclear. This was examined in the present study in a mouse model of hypertension induced in Smad3 knockout (KO) and wild-type (WT) mice by subcutaneous angiotensin II infusion and in vitro in mesangial cells lacking Smad3. After angiotensin II infusion, both Smad3 KO and WT mice developed equally high levels of blood pressure. However, disruption of Smad3 prevented angiotensin II-induced kidney injury by lowering albuminuria and serum creatinine (P < 0.01), inhibiting renal fibrosis such as collagen type I and IV, fibronectin, and α-SMA expression (all P < 0.01), and blocking renal inflammation including macrophage and T cell infiltration and upregulation of IL-1β, TNF-α, and monocyte chemoattractant protein-1 in vivo and in vitro (all P < 0.001). Further studies revealed that blockade of angiotensin IIinduced renal transforming growth factor (TGF)-β1 expression and inhibition of Smurf2-mediated degradation of renal Smad7 are mechanisms by which Smad3 KO mice were protected from angiotensin II-induced renal fibrosis and NF-κB-driven renal inflammation in vivo and in vitro. In conclusion, Smad3 is a key mediator of hypertensive nephropathy. Smad3 promotes Smurf2-dependent ubiquitin degradation of renal Smad7, thereby enhancing angiotensin II-induced TGF- β/Smad3-mediated renal fibrosis and NF-κB-driven renal inflammation. Results from this study suggest that inhibition of Smad3 or overexpression of Smad7 may be a novel therapeutic strategy for hypertensive nephropathy. [ABSTRACT FROM AUTHOR]

Introduction and Aims: Elevated plasma levels of C-reactive protein (CRP) are closely associated with progressive renal injury in patients with chronic kidney disease (CKD). Here, we tested a hypothesis that CRP may promote renal fibrosis and inflammation via a TGF-β/Smad3-dependent mechanism. Methods: Role and mechanisms of TGF-β/Smad3 in CRP-induced renal fibrosis and inflammation were examined in a mouse model of unilateral ureteral obstruction (UUO) induced in CRP Tg/Smad3 KO mice and in a rat tubular epithelial cell line in which Smad3 gene is stably knocked down (S3KD-NRK52E). Results: We found that mice overexpressing the human CRP gene were largely promoted renal inflammation and fibrosis as evidenced by increasing IL-1β, TNF-α, MCP-1 expression, F4/80 + macrophages infiltration, and marked accumulation of α-smooth muscle actin (α-SMA), collagen I and fibronectin in the UUO kidney, which were blunted when Smad3 gene was deleted in CRPtg-Smad3KO. Mechanistically, we found that the protection of renal inflammation and fibrosis in the UUO kidney of CRPtg-Smad3KO mice was associated with the inactivation of CD32-NF-κB and TGF-β/Smad3 signaling. Conclusion: In conclusion, Smad3 deficiency protects against CRP-mediated renal inflammation and fibrosis in the UUO kidney by inactivating CD32-NF-κB and TGF-β/Smad3 signaling., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)