Acute kidney injury (AKI) is a complex disorder for which currently there is no accepted definition. Having a uniform standard for diagnosing and classifying AKI would enhance our ability to manage these patients. Future clinical and translational research in AKI will require collaborative networks of investigators drawn from various disciplines, dissemination of information via multidisciplinary joint conferences and publications, and improved translation of knowledge from pre-clinical research. We describe an initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI. Members representing key societies in critical care and nephrology along with additional experts in adult and pediatric AKI participated in a two day conference in Amsterdam, The Netherlands, in September 2005 and were assigned to one of three workgroups. Each group's discussions formed the basis for draft recommendations that were later refined and improved during discussion with the larger group. Dissenting opinions were also noted. The final draft recommendations were circulated to all participants and subsequently agreed upon as the consensus recommendations for this report. Participating societies endorsed the recommendations and agreed to help disseminate the results. The term AKI is proposed to represent the entire spectrum of acute renal failure. Diagnostic criteria for AKI are proposed based on acute alterations in serum creatinine or urine output. A staging system for AKI which reflects quantitative changes in serum creatinine and urine output has been developed. We describe the formation of a multidisciplinary collaborative network focused on AKI. We have proposed uniform standards for diagnosing and classifying AKI which will need to be validated in future studies. The Acute Kidney Injury Network offers a mechanism for proceeding with efforts to improve patient outcomes.

Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury

Transforming growth factor-β (TGF-β) is the primary factor that drives fibrosis in most, if not all, forms of chronic kidney disease (CKD). Inhibition of the TGF-β isoform, TGF-β1, or its downstream signalling pathways substantially limits renal fibrosis in a wide range of disease models whereas overexpression of TGF-β1 induces renal fibrosis. TGF-β1 can induce renal fibrosis via activation of both canonical (Smad-based) and non-canonical (non-Smad-based) signalling pathways, which result in activation of myofibroblasts, excessive production of extracellular matrix (ECM) and inhibition of ECM degradation. The role of Smad proteins in the regulation of fibrosis is complex, with competing profibrotic and antifibrotic actions (including in the regulation of mesenchymal transitioning), and with complex interplay between TGF-β/Smads and other signalling pathways. Studies over the past 5 years have identified additional mechanisms that regulate the action of TGF-β1/Smad signalling in fibrosis, including short and long noncoding RNA molecules and epigenetic modifications of DNA and histone proteins. Although direct targeting of TGF-β1 is unlikely to yield a viable antifibrotic therapy due to the involvement of TGF-β1 in other processes, greater understanding of the various pathways by which TGF-β1 controls fibrosis has identified alternative targets for the development of novel therapeutics to halt this most damaging process in CKD.

TGF-β: the master regulator of fibrosis

Epithelial–mesenchymal transition (EMT) is a cellular programme that is known to be crucial for embryogenesis, wound healing and malignant progression. During EMT, cell–cell and cell–extracellular matrix interactions are remodelled, which leads to the detachment of epithelial cells from each other and the underlying basement membrane, and a new transcriptional programme is activated to promote the mesenchymal fate. In the context of neoplasias, EMT confers on cancer cells increased tumour-initiating and metastatic potential and a greater resistance to elimination by several therapeutic regimens. In this Review, we discuss recent findings on the mechanisms and roles of EMT in normal and neoplastic tissues, and the cell-intrinsic signals that sustain expression of this programme. We also highlight how EMT gives rise to a variety of intermediate cell states between the epithelial and the mesenchymal state, which could function as cancer stem cells. In addition, we describe the contributions of the tumour microenvironment in inducing EMT and the effects of EMT on the immunobiology of carcinomas. Epithelial–mesenchymal transition (EMT) is crucial for embryogenesis, wound healing and cancer development, and confers greater resistance to cancer therapies. This Review discusses the mechanisms of EMT and its roles in normal and neoplastic tissues, the contribution of cell-intrinsic signals and the microenvironment to inducing EMT, and its effects on the immunobiology of carcinomas.

New insights into the mechanisms of epithelial–mesenchymal transition and implications for cancer

https://www.kidney-international.org/article/S0085-2538(15)53124-4/pdf

Cisplatin nephrotoxicity: Mechanisms and renoprotective strategies

OVERVIEW The GRA Marketing Internship Program is offered to students who are interested in gaining valuable work experience through efforts in marketing, membership, sales, and events. Interns work directly to assist the Director of Marketing and Communications on various tasks relating to upcoming GRA events. During this internship, students will work a minimum of 10 hours a week and a maximum of 20 hours a week. Students are encouraged to earn credit for their internship, however this is a paid internship. Students interested in obtaining credit for their internship must consult their academic advisor or the intern coordinator at their academic unit.

Role of WHO.

Extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), which are members of the mitogen-activated protein kinase superfamily, have been well characterized and are known to be involved in cell survival; however, recent evidence suggests that the activation of ERK1/2 also contributes to cell death in some cell types and organs under certain conditions. For example, ERK1/2 is activated in neuronal and renal epithelial cells upon exposure to oxidative stress and toxicants and deprivation of growth factors, and inhibition of the ERK pathway blocks apoptosis. ERK activation also occurs in animal models of ischemia- and trauma-induced brain injury and cisplatin-induced renal injury, and inactivation of ERK reduces the extent of tissue damage. In some studies, ERK has been implicated in apoptotic events upstream of mitochondrial cytochrome c release, whereas other studies have suggested the converse that ERK acts downstream of mitochondrial events and upstream of caspase-3 activation. ERK also can contribute to cell death through the suppression of the antiapoptotic signaling molecule Akt. Here we summarize the evidence and mechanism of ERK-induced apoptosis in both cell culture and in animal models.

https://jpet.aspetjournals.org/content/jpet/early/2006/06/26/jpet.106.107367.full.pdf

A Death-Promoting Role for Extracellular Signal-Regulated Kinase

https://www.kidney-international.org/article/S0085-2538(15)54539-0/pdf

A novel STAT3 inhibitor, S3I-201, attenuates renal interstitial fibroblast activation and interstitial fibrosis in obstructive nephropathy

Activation of renal interstitial fibroblasts is critically involved in the development of tubulointerstitial fibrosis in chronic kidney diseases. In this study, we investigated the effect of trichostatin A (TSA), a specific histone deacetylase (HDAC) inhibitor, on the activation of renal interstitial fibroblasts in a rat renal interstitial fibroblast line (NRK-49F) and the development of renal fibrosis in a murine model of unilateral ureteral obstruction (UUO). α-Smooth muscle actin (α-SMA) and fibronectin, two hallmarks of fibroblast activation, were highly expressed in cultured NRK-49F cells, and their expression was inhibited in the presence of TSA. Similarly, administration of TSA suppressed the expression of α-SMA and fibronectin and attenuated the accumulation of renal interstitial fibroblasts in the kidney after the obstructive injury. Activation of renal interstitial fibroblasts was accompanied by phosphorylation of signal transducer and activator of transcription 3 (STAT3), and TSA treatment also abolished these responses. Furthermore, inhibition of the STAT3 pathway with AG490 inhibited expression of α-SMA and fibronectin in NRK-49F cells. Finally, TSA treatment inhibited tubular cell apoptosis and caspase-3 activation in the obstructive kidney. Collectively, we suggest that pharmacological HDAC inhibition may induce antifibrotic activity by inactivation of renal interstitial fibroblasts and inhibition of renal tubular cell death. STAT3 may mediate those actions of HDACs.

https://www.physiology.org/doi/pdf/10.1152/ajprenal.00282.2009

Inhibition of histone deacetylase activity attenuates renal fibroblast activation and interstitial fibrosis in obstructive nephropathy

HDACs (histone deacetylases) are a group of enzymes that deacetylate histones as well as non-histone proteins. They are known as modulators of gene transcription and are associated with proliferation and differentiation of a variety of cell types and the pathogenesis of some diseases. Recently, HDACs have come to be considered crucial targets in various diseases, including cancer, interstitial fibrosis, autoimmune and inflammatory diseases, and metabolic disorders. Pharmacological inhibitors of HDACs have been used or tested to treat those diseases. In the present review, we will examine the application of HDAC inhibitors in a variety of diseases with the focus on their effects of anti-cancer, fibrosis, anti-inflammatory, immunomodulatory activity and regulating metabolic disorders.

/pdf/histone-deacetylases-as-targets-for-treatment-of-multiple-3jmhyojkom.pdf

Histone deacetylases as targets for treatment of multiple diseases

Reactive oxygen species, including hydrogen peroxide (H2O2), are generated during ischemia-reperfusion and are critically involved in acute renal failure. The present studies examined the role of t...

https://www.physiology.org/doi/pdf/10.1152/ajprenal.00170.2006

Shougang Zhuang

Papers

A Death-Promoting Role for Extracellular Signal-Regulated Kinase

A novel STAT3 inhibitor, S3I-201, attenuates renal interstitial fibroblast activation and interstitial fibrosis in obstructive nephropathy

Inhibition of histone deacetylase activity attenuates renal fibroblast activation and interstitial fibrosis in obstructive nephropathy

Histone deacetylases as targets for treatment of multiple diseases

ERK promotes hydrogen peroxide-induced apoptosis through caspase-3 activation and inhibition of Akt in renal epithelial cells