Renal fibrosis: collagen composition and assembly regulates epithelial-mesenchymal transdifferentiation

Simultaneous Occurrence of Collagen Type III Glomerulopathy and Immunoglobulin A Nephropathy: A Rare Case Report

BACKGROUND Collagen type III glomerulopathy (CG) is a rare disease with poorly understood pathogenesis, usually identified by abnormal collagen type III accumulation in glomeruli and manifesting as progressive deterioration of kidney function with nephrotic-range proteinuria. Immunoglobulin A nephropathy (IgAN) is the most prevalent glomerulopathy worldwide and is a leading cause of end-stage renal disease as a result of progressive fibrotic changes. Fibrosis is primarily caused by collagen type III deposition, which may explain the simultaneous occurrence of IgAN and CG. CASE REPORT A young man presented with clinical and laboratory evidence of chronic kidney injury, including long-term nephrotic-range proteinuria and microscopic hematuria. Partial improvement in proteinuria was achieved with steroid therapy and conservative management. As the non-invasive workup was inconclusive, and a complete recovery of kidney function was not achieved, a kidney biopsy was done. Histopathological microscopic examination revealed advanced IgA nephropathy, Oxford classification M0E1S1T2C0, with features highly suggestive of type III collagen glomerulopathy. CONCLUSIONS We described a case of collagen type III glomerulopathy, also known as collagenofibrotic glomerulopathy, and its association with concurrent immunoglobulin A nephropathy in a healthy man presenting with chronic proteinuria and microscopic hematuria. As the number of reported cases in the Middle East is rising, we present this report to improve understanding and greater recognition of such cases.

Collagen type IV alpha 1 chain (COL4A1) expression in the developing human lung

BACKGROUND

Collagen type IV alpha 1 chain (COL4A1) in the basement membrane is an important component during lung development, as suggested from animal models where COL4A1 has been shown to regulate alveolarization and angiogenesis. Less is known about its role in human lung development. Our aim was to study COL4A1 expression in preterm infants with different lung maturational and clinical features.

METHODS

COL4A1 expression in 115 lung samples from newborn infants (21-41 weeks' gestational age; 0-228 days' postnatal age [PNA]) was studied by immunohistochemistry combined with digital image analysis. Cluster analysis was performed to find subgroups according to immunohistologic and clinical data.

RESULTS

Patients were automatically categorized into 4 Groups depending on their COL4A1 expression. Expression of COL4A1 was mainly extracellular in Group 1, low in Group 2, intracellular in Group 3, and both extra- and intracellular in Group 4. Intracellular/extracellular ratio of COL4A1 expression related to PNA showed a distinctive postnatal maturational pattern on days 1-7, where intracellular expression of COL4A1 was overrepresented in extremely preterm infants.

CONCLUSIONS

COL4A1 expression seems to be highly dynamic during the postnatal life due to a possible rapid remodeling of the basement membrane. Intracellular accumulation of COL4A1 in the lungs of extremely premature infants occurs more frequently between 1 and 7 postnatal days than during the first 24 hours. In view of the lung arrest described in extremely preterm infants, the pathological and/or developmental role of postnatally increased intracellular COL4A1 as marker for basement membrane turnover, needs to be further investigated.

LncRNA NEAT1 accelerates renal fibrosis progression via targeting miR-31 and modulating RhoA/ROCK signal pathway

Renal fibrosis is the final pathway for chronic kidney disease to end-stage renal failure. Noncoding RNAs have been reported to play a crucial role in renal fibrosis. Here, the effects of long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) and miR-31 on renal fibrosis and their regulatory mechanism were evaluated. RT-qPCR was used to assess NEAT1, miR-31, and RhoA levels. Western blot was performed to analyze the expression of fibrosis markers, RhoA, rho-related kinase (ROCK1), and connective tissue growth factor (CTGF). RNA immunoprecipitation (RIP), fluorescence in situ hybridization (FISH), and luciferase reporter assays verified the interaction between miR-31 and NEAT1 or RhoA. Renal fibrosis and injury were observed by Masson and hematoxylin and eosin (H&E) staining. The expression level of inflammatory cytokines was detected by ELISA. Immunohistochemistry (IHC) was performed to examine the expression levels of α-smooth muscle actin (α-SMA) and RhoA in renal tissues. We showed that NEAT1 was highly expressed, whereas miR-31 was decreased in renal fibrosis. NEAT1 was found to directly bind miR-31 to positively regulate RhoA expression. Furthermore, NEAT1 silencing inhibited renal fibrosis and inflammation and suppressed the RhoA/ROCK1 signaling pathway. However, knockdown of miR-31 could reverse these effects. NEAT1 silencing or overexpression of miR-31 alleviated renal fibrosis in vivo. In conclusion, NEAT1 accelerates renal fibrosis progression via negative regulation of miR-31 and the activation of RhoA/ROCK1 pathway, thereby upregulating the expression level of CTGF, providing a theoretical basis for treatment and prognostic evaluation of renal fibrosis.

Regulation of epithelial-mesenchymal transition by tumor microenvironmental signals and its implication in cancer therapeutics

Epithelial-mesenchymal transition (EMT) has been implicated in various aspects of tumor development, including tumor invasion and metastasis, cancer stemness, and therapy resistance. Diverse stroma cell types along with biochemical and biophysical factors in the tumor microenvironment impinge on the EMT program to impact tumor progression. Here we provide an in-depth review of various tumor microenvironmental signals that regulate EMT in cancer. We discuss the molecular mechanisms underlying the role of EMT in therapy resistance and highlight new therapeutic approaches targeting the tumor microenvironment to impact EMT and tumor progression.

Glucosidase inhibitor, Nimbidiol ameliorates renal fibrosis and dysfunction in type-1 diabetes

Diabetic nephropathy is characterized by excessive accumulation of extracellular matrix (ECM) leading to renal fibrosis, progressive deterioration of renal function, and eventually to end stage renal disease. Matrix metalloproteinases (MMPs) are known to regulate synthesis and degradation of the ECM. Earlier, we demonstrated that imbalanced MMPs promote adverse ECM remodeling leading to renal fibrosis in type-1 diabetes. Moreover, elevated macrophage infiltration, pro-inflammatory cytokines and epithelial‒mesenchymal transition (EMT) are known to contribute to the renal fibrosis. Various bioactive compounds derived from the medicinal plant, Azadirachta indica (neem) are shown to regulate inflammation and ECM proteins in different diseases. Nimbidiol is a neem-derived diterpenoid that is considered as a potential anti-diabetic compound due to its glucosidase inhibitory properties. We investigated whether Nimbidiol mitigates adverse ECM accumulation and renal fibrosis to improve kidney function in type-1 diabetes and the underlying mechanism. Wild-type (C57BL/6J) and type-1 diabetic (C57BL/6-Ins2^Akita/J) mice were treated either with saline or with Nimbidiol (0.40 mg kg^-1 d^-1) for eight weeks. Diabetic kidney showed increased accumulation of M1 macrophages, elevated pro-inflammatory cytokines and EMT. In addition, upregulated MMP-9 and MMP-13, excessive collagen deposition in the glomerular and tubulointerstitial regions, and degradation of vascular elastin resulted to renal fibrosis in the Akita mice. These pathological changes in the diabetic mice were associated with functional impairments that include elevated resistive index and reduced blood flow in the renal cortex, and decreased glomerular filtration rate. Furthermore, TGF-β1, p-Smad2/3, p-P38, p-ERK1/2 and p-JNK were upregulated in diabetic kidney compared to WT mice. Treatment with Nimbidiol reversed the changes to alleviate inflammation, ECM accumulation and fibrosis and thus, improved renal function in Akita mice. Together, our results suggest that Nimbidiol attenuates inflammation and ECM accumulation and thereby, protects kidney from fibrosis and dysfunction possibly by inhibiting TGF-β/Smad and MAPK signaling pathways in type-1 diabetes.

The extracellular matrix alteration, implication in modulation of drug resistance mechanism: friends or foes?

The extracellular matrix (ECM) is an important component of the tumor microenvironment (TME), having several important roles related to the hallmarks of cancer. In cancer, multiple components of the ECM have been shown to be altered. Although most of these alterations are represented by the increased or decreased quantity of the ECM components, changes regarding the functional alteration of a particular ECM component or of the ECM as a whole have been described. These alterations can be induced by the cancer cells directly or by the TME cells, with cancer-associated fibroblasts being of particular interest in this regard. Because the ECM has this wide array of functions in the tumor, preclinical and clinical studies have assessed the possibility of targeting the ECM, with some of them showing encouraging results. In the present review, we will highlight the most relevant ECM components presenting a comprehensive description of their physical, cellular and molecular properties which can alter the therapy response of the tumor cells. Lastly, some evidences regarding important biological processes were discussed, offering a more detailed understanding of how to modulate altered signalling pathways and to counteract drug resistance mechanisms in tumor cells.

Twist-related protein 1 induces epithelial-mesenchymal transition and renal fibrosis through the upregulation of complement 3

We have demonstrated that complement 3 (C3) is upregulated and induces epithelial-mesenchymal transition (EMT) phenomenon and renal fibrosis in unilateral ureteral obstruction (UUO) kidney. We investigated roles of twist-related protein 1 (TWIST1) in EMT phenomenon and renal fibrosis through C3 upregulation in a mouse UUO model with gene silencer pyrrole-imidazole (PI) polyamides targeting TWIST1. We designed and synthesized PI polyamides targeting TWIST1 binding site on mouse pre-pro C3 promoter. Increased expression C3 mRNA with interferon-γ was significantly inhibited with PI polyamide in nephrotubular epithelial cells. Immunofluorescence showed suppression of E-cadherin and enhancement of α-smooth muscle actin (α-SMA) stainings as EMT phenomena in UUO kidney. TWIST1 and C3 expression was significantly increased in UUO kidney versus contralateral unobstructed kidney (CUK). Expression of transforming growth factor-β1 (TGF-β1), α-SMA and renin mRNAs was increased in UUO kidney versus CUK. Systemic administration of TWIST1 PI polyamide significantly suppressed increased C3 expression in UUO kidney versus CUK. PI polyamide administration also suppressed the increased expression of TGF-β1, α-SMA and renin mRNAs and histologically improved renal fibrosis in UUO kidney. These findings indicate that TWIST1 induces EMT phenomenon and renal fibrosis by TGF-β1 upregulation of C3 in mouse UUO model and that TWIST1 PI polyamide may be a novel medicine for renal fibrosis.

Loss of MEN1 leads to renal fibrosis and decreases HGF-Adamts5 pathway activity via an epigenetic mechanism

BACKGROUND

Renal fibrosis is a serious condition that results in the development of chronic kidney diseases. The MEN1 gene is an epigenetic regulator that encodes the menin protein and its role in kidney tissue remains unclear.

METHODS

Kidney histology was examined on paraffin sections stained with hematoxylin-eosin staining. Masson's trichrome staining and Sirius red staining were used to analyze renal fibrosis. Gene and protein expression were determined by quantitative real-time PCR (qPCR) and Western blot, respectively. Immunohistochemistry staining in the kidney tissues from mice or patients was used to evaluate protein levels. Flow cytometry was used to analyze the cell cycle distributions and apoptosis. RNA-sequencing was performed for differential expression genes in the kidney tissues of the Men1f/f and Men1∆/∆ mice. Chromatin immunoprecipitation sequencing (ChIP-seq) was carried out for identification of menin- and H3K4me3-enriched regions within the whole genome in the mouse kidney tissue. ChIP-qPCR assays were performed for occupancy of menin and H3K4me3 at the gene promoter regions. Luciferase reporter assay was used to detect the promoter activity. The exacerbated unilateral ureteral obstruction (UUO) models in the Men1f/f and Men1∆/∆ mice were used to assess the pharmacological effects of rh-HGF on renal fibrosis.

RESULTS

The expression of MEN1 is reduce in kidney tissues of fibrotic mouse and human diabetic patients and treatment with fibrotic factor results in the downregulation of MEN1 expression in renal tubular epithelial cells (RTECs). Disruption of MEN1 in RTECs leads to high expression of α-SMA and Collagen 1, whereas MEN1 overexpression restrains epithelial-to-mesenchymal transition (EMT) induced by TGF-β treatment. Conditional knockout of MEN1 resulted in chronic renal fibrosis and UUO-induced tubulointerstitial fibrosis (TIF), which is associated with an increased induction of EMT, G2/M arrest and JNK signaling. Mechanistically, menin recruits and increases H3K4me3 at the promoter regions of hepatocyte growth factor (HGF) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (Adamts5) genes and enhances their transcriptional activation. In the UUO mice model, exogenous HGF restored the expression of Adamts5 and ameliorated renal fibrosis induced by Men1 deficiency.

CONCLUSIONS

These findings demonstrate that MEN1 is an essential antifibrotic factor in renal fibrogenesis and could be a potential target for antifibrotic therapy.

Sirtuins and Hypoxia in EMT Control

Epithelial–mesenchymal transition (EMT), a physiological process during embryogenesis, can become pathological in the presence of different driving forces. Reduced oxygen tension or hypoxia is one of these forces, triggering a large number of molecular pathways with aberrant EMT induction, resulting in cancer and fibrosis onset. Both hypoxia-induced factors, HIF-1α and HIF-2α, act as master transcription factors implicated in EMT. On the other hand, hypoxia-dependent HIF-independent EMT has also been described. Recently, a new class of seven proteins with deacylase activity, called sirtuins, have been implicated in the control of both hypoxia responses, HIF-1α and HIF-2α activation, as well as EMT induction. Intriguingly, different sirtuins have different effects on hypoxia and EMT, acting as either activators or inhibitors, depending on the tissue and cell type. Interestingly, sirtuins and HIF can be activated or inhibited with natural or synthetic molecules. Moreover, recent studies have shown that these natural or synthetic molecules can be better conveyed using nanoparticles, representing a valid strategy for EMT modulation. The following review, by detailing the aspects listed above, summarizes the interplay between hypoxia, sirtuins, and EMT, as well as the possible strategies to modulate them by using a nanoparticle-based approach.

Ginkgo biloba leaf extract mitigates cisplatin-induced chronic renal interstitial fibrosis by inhibiting the epithelial-mesenchymal transition of renal tubular epithelial cells mediated by the Smad3/TGF-β1 and Smad3/p38 MAPK pathways

Background

Our previous study indicated that Ginkgo biloba leaf extract (EGb) could protect against cisplatin-induced acute kidney injury in rabbits. The present study aimed to determine the effects and potential molecular mechanisms of EGb on chronic renal interstitial fibrosis induced by cisplatin using in vivo and in vitro models.

Methods

Rats received a single dose of cisplatin on Day 1, and a subset of rats was intraperitoneally injected with EGb daily between Days 22–40. In vitro, HK-2 cells were treated with cisplatin, and a subset of cells was cultivated with EGb or SIS3 (Smad3 inhibitor) for 48 h. Renal function of rats was assessed by detecting the levels of serum creatinine (Scr), blood urea nitrogen (BUN) and urinary N-acetyl-β-D-glucosaminidase (NAG). Hematoxylin and eosin staining and Masson’s trichrome staining were used to evaluate the damage and fibrosis of renal tissue. Western blotting, immunohistochemistry and immunofluorescence were used to detect the protein levels of fibrosis-associated proteins and signaling pathway-related proteins. RT–qPCR analysis was used to examine the mRNA levels of related indicators.

Results

EGb significantly decreased the increased levels of Scr, BUN and urinary NAG and attenuated renal damage and the relative area of renal interstitial fibrosis induced by cisplatin. Additionally, EGb decreased the protein levels of α-SMA, Col I, TGF-β1, smad2/3, phosphorylated (p)-smad2/3, p38 MAPK, and p-p38 MAPK; the ratio of p-p38 MAPK/p38 MAPK; and the mRNA level of p38 MAPK in renal tissues induced by cisplatin. In agreement with in vivo studies, EGb significantly reduced the increased protein levels of these indicators. Additionally, EGb significantly reduced the increased protein levels of vimentin, TIMP-1, and CTGF, as well as the mRNA levels of α-SMA, vimentin, and TGF-β1, while it significantly increased the reduced E-cadherin protein level and the MMP-1/TIMP-1 ratio in HK-2 cells induced by cisplatin. It’s worth noting that the effects of SIS3 in changing the above indicators were similar to those of EGb.

Conclusion

Our study demonstrated that EGb improved cisplatin-induced chronic renal interstitial fibrosis, and its mechanisms were associated with inhibiting the epithelial-mesenchymal transition of renal tubular epithelial cells via the Smad3/TGF-β1 and Smad3/p38 MAPK pathways.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00574-y.

Mitochondrial Pathophysiology on Chronic Kidney Disease

In healthy kidneys, interstitial fibroblasts are responsible for the maintenance of renal architecture. Progressive interstitial fibrosis is thought to be a common pathway for chronic kidney diseases (CKD). Diabetes is one of the boosters of CKD. There is no effective treatment to improve kidney function in CKD patients. The kidney is a highly demanding organ, rich in redox reactions occurring in mitochondria, making it particularly vulnerable to oxidative stress (OS). A dysregulation in OS leads to an impairment of the Electron transport chain (ETC). Gene deficiencies in the ETC are closely related to the development of kidney disease, providing evidence that mitochondria integrity is a key player in the early detection of CKD. The development of novel CKD therapies is needed since current methods of treatment are ineffective. Antioxidant targeted therapies and metabolic approaches revealed promising results to delay the progression of some markers associated with kidney disease. Herein, we discuss the role and possible origin of fibroblasts and the possible potentiators of CKD. We will focus on the important features of mitochondria in renal cell function and discuss their role in kidney disease progression. We also discuss the potential of antioxidants and pharmacologic agents to delay kidney disease progression.

Epithelial-Mesenchymal Transition-Inducing Factors Involved in the Progression of Lung Cancers

Although there have been advances in cancer therapy and surgical improvement, lung cancer has the lowest survival rate (19%) at all stages. This is because most patients are diagnosed with concurrent metastasis, which occurs due to numerous related reasons. Especially, lung cancer is one of the most common and malignant cancers in the world. Although there are advanced therapeutic strategies, lung cancer remains one of the main causes of cancer death. Recent work has proposed that epithelial-mesenchymal transition (EMT) is the main cause of metastasis in most cases of human cancers including lung cancer. EMT involves the conversion of epithelial cells, wherein the cells lose their epithelial abilities and become mesenchymal cells involved in embryonic development, such as gastrulation and neural crest formation. In addition, recent research has indicated that EMT contributes to altering the cancer cells into cancer stem cells (CSCs). Although EMT is important in the developmental stages, this process also activates lung cancer progression, including complicated and diverse signaling pathways. Despite the numerous investigations on signaling pathways involved in the progression of lung cancer, this malignancy is considered critical for treatment. EMT in lung cancer involves many transcription factors and inducers, for example, Snail, TWIST, and ZEB are the master regulators of EMT. EMT-related factors and signaling pathways are involved in the progression of lung cancer, proposing new approaches to lung cancer therapy. In the current review, we highlight the signaling pathways implicated in lung cancer and elucidate the correlation of these pathways, indicating new insights to treat lung cancer and other malignancies.

LncRNA SPANXA2-OT1 Participates in the Occurrence and Development of EMT in Calcium Oxalate Crystal-Induced Kidney Injury by Adsorbing miR-204 and Up-Regulating Smad5

Objective: To explore the regulatory mechanism of long non-coding RNAs (lncRNAs) in the occurrence and development of epithelial-mesenchymal transition (EMT) in calcium oxalate crystal-induced kidney injury. Materials and Methods: Gene core technique was used to screen differentially expressed lncRNAs and mRNAs in HK-2 cells before and after calcium oxalate monohydrate (COM) stimulation; differentially expressed mRNAs were then analyzed using GO and pathway analysis. The role of target lncRNA in EMT in renal tubular epithelial cells induced by COM was further investigated by applying a series of in vitro experiments. Results: Four differentially expressed lncRNAs (ABCA9-AS1, SPANXA2-OT1, RP11-955H22.1, and RP11-748C4.1) were up-regulated after 48 h of COM stimulation compared to the control group, where up-regulated expression of lncRNA SPANXA2-OT1 was the most significant. Thus, lncRNA SPANXA2-OT1 was further examined. Interference lncRNA SPANXA2-OT1 reversed the down-regulation of E-cadherin and Pan-ck, and up-regulated Vimentin and α-SMA induced by COM stimulation. The application of miR204 inhibitor weakened the interference effect of interfering RNA on lncRNA SPANXA2-OT1 and promoted the occurrence of EMT. Moreover, the miR204 simulator alleviated the overexpression effect of lncRNA SPANXA2-OT1 on COM-stimulated renal tubular epithelial cells and inhibited the occurrence of EMT in renal tubular epithelial cells. Also, a dual-luciferase reporter assay showed that miR-204 could bind to lncRNA SPANXA2-OT1 and Smad5, while lncRNA SPANXA2-OT1 could inhibit cell proliferation and promote cell apoptosis. Conclusion: The lncRNA SPANXA2-OT1 is involved in the occurrence and development of EMT in renal tubular epithelial cells induced by crystalline kidney injury by adsorbing miR-204 and up-regulating Smad5.

GYY4137 Regulates Extracellular Matrix Turnover in the Diabetic Kidney by Modulating Retinoid X Receptor Signaling

Diabetic kidney is associated with an accumulation of extracellular matrix (ECM) leading to renal fibrosis. Dysregulation of retinoic acid metabolism involving retinoic acid receptors (RARs) and retinoid X receptors (RXRs) has been shown to play a crucial role in diabetic nephropathy (DN). Furthermore, RARs and peroxisome proliferator-activated receptor γ (PPARγ) are known to control the RXR-mediated transcriptional regulation of several target genes involved in DN. Recently, RAR and RXR have been shown to upregulate plasminogen activator inhibitor-1 (PAI-1), a major player involved in ECM accumulation and renal fibrosis during DN. Interestingly, hydrogen sulfide (H₂S) has been shown to ameliorate adverse renal remodeling in DN. We investigated the role of RXR signaling in the ECM turnover in diabetic kidney, and whether H₂S can mitigate ECM accumulation by modulating PPAR/RAR-mediated RXR signaling. We used wild-type (C57BL/6J), diabetic (C57BL/6-Ins2^Akita/J) mice and mouse mesangial cells (MCs) as experimental models. GYY4137 was used as a H₂S donor. Results showed that in diabetic kidney, the expression of PPARγ was decreased, whereas upregulations of RXRα, RXRβ, and RARγ1 expression were observed. The changes were associated with elevated PAI-1, MMP-9 and MMP-13. In addition, the expressions of collagen IV, fibronectin and laminin were increased, whereas elastin expression was decreased in the diabetic kidney. Excessive collagen deposition was observed predominantly in the peri-glomerular and glomerular regions of the diabetic kidney. Immunohistochemical localization revealed elevated expression of fibronectin and laminin in the glomeruli of the diabetic kidney. GYY4137 reversed the pathological changes. Similar results were observed in in vitro experiments. In conclusion, our data suggest that RXR signaling plays a significant role in ECM turnover, and GYY4137 modulates PPAR/RAR-mediated RXR signaling to ameliorate PAI-1-dependent adverse ECM turnover in DN.

Suppression of collagen IV alpha-2 subunit by prolyl hydroxylase domain inhibition via hypoxia-inducible factor-1 in chronic kidney disease

Elevation of hypoxia-inducible factor 1 protein has been shown to be protective in acute kidney injury and HIF1α enhancing drug therapies are currently in clinical trials for the treatment of anemia of chronic kidney disease. Despite its benefits, long-term HIF1 elevation seems to be associated with additional effects in the kidneys such as tubulointerstitial fibrosis. To better understand the effects of prolonged HIF1 exposure, assessment of baseline and post-therapy levels of HIF1α and other related biomarkers is essential. In this study, we assessed the effect of HIF1α enhancement using prolyl hydroxylase inhibitor (PHD-I) DMOG, on a key profibrotic marker of kidney disease. In specific, we examined the change in expression of Collagen 4 subunit A2 in cultured urinary cells of CKD patients pre and post 24-hour exposure to 1mM DMOG. Our results show that besides HIF1α enhancement, COL4A2 protein is suppressed in presence of DMOG. To determine if this effect is mediated by HIF1, we used HIF1α gene silencing in HEK293 cells and examined the effect of DMOG on protein and gene expression of COL4A2 post 24-hour exposure. We showed that silencing HIF1α reverses and amplifies the expression of COL4A2 in HEK293 cells. Our data suggest that HIF1 directly regulates the expression of COL4A2 in kidney cells and that HIF1α enhancing therapy has suppressive effects on COL4A2 that may be clinically relevant and must be considered in determining the safety and efficacy of these drugs in the treatment of anemia.

The functional cross talk between cancer cells and cancer associated fibroblasts from a cancer mechanics perspective

The function of biological tissues in health and disease is regulated at cellular level and is highly influenced by the physical microenvironment, through the interaction of forces between cells and ECM, which are perceived through mechanosensing pathways. In cancer, both chemical and physical signaling cascades and their interactions are involved during cell-cell and cell-ECM communications to meet requirements of tumor growth. Among stroma cells, cancer associated fibroblasts (CAFs) play key role in tumor growth and pave the way for cancer cells to initiate metastasis and invasion to other tissues, and without recruitment of CAFs, the process of cancer invasion is dysfunctional. This is through an intense chemical and physical cross talks with tumor cells, and interactive remodeling of ECM. During such interaction CAFs apply traction forces and depending on the mechanical properties, deform ECM and in return receive physical signals from the micromechanical environment. Such interaction leads to ECM remodeling by manipulating ECM structure and its mechanical properties. The results are in form of deposition of extra fibers, stiffening, rearrangement and reorganization of fibrous structure, and degradation which are due to a complex secretion and expression of different markers triggered by mechanosensing of tumor cells, specially CAFs. Such events define cancer progress and invasion of cancer cells. A systemic knowledge of chemical and physical factors provides a holistic view of how cancer process and enhances the current treatment methods to provide more diversity among targets that involves tumor cells and ECM structure.

Renal protective effects and mechanisms of the angiotensin receptor-neprilysin inhibitor LCZ696 in mice with cardiorenal syndrome

AIMS

This study investigated the renal protective effects and mechanisms of angiotensin receptor-neprilysin inhibitor LCZ696 in mice with cardiorenal syndrome.

MATERIALS AND METHODS

Mice were divided into abdominal aortic ligation alone, or treatment with LCZ696 or valsartan, whilst those undergoing sham surgery served as controls. Rat proximal renal tubular epithelial cells from the NRK-52E line were treated with control solution, LCZ696 or valsartan, in the presence or absence of Ang II for 24 h.

KEY FINDINGS

Compared to controls, abdominal aortic ligation significantly increased plasma NT-proBNP and urine neutrophil gelatinase-associated lipocalin (NGAL), which were associated with reduced renal length and velocity time integral on ultrasonography. Histology revealed wrinkling of the glomerular capillary wall and sclerosis of the glomerulus, dilatation of the Bowman's capsule, accompanied by diffuse renal tubular atrophy and fibrosis, accompanied by lower kidney index and higher percentage area of fibrosis. Increases in NGAL and decreased ANP protein and mRNA expression levels were observed. These abnormalities were significantly prevented by LCZ696 and to a lesser extent by valsartan. Cellular experiments demonstrated a central role of Ang II/transforming growth factor-β1/Smad2/3/connective tissue growth factor-dependent signaling leading to type IV collagen deposition. This upregulation was reversed by LCZ696 in a greater extent than valsartan treatment alone, accompanied by a significant improvement in NGAL.

SIGNIFICANCE

LCZ696 can reduce kidney injury to a level beyond valsartan therapy alone in mice with cardiorenal syndrome, which can be speculated by effects on epithelial-mesenchymal transition and fibrosis through downregulating the TGF-β1/Smad2/3/CTGF/Collagen IV pathway.

Identification of Gene Signatures and Expression Patterns During Epithelial-to-Mesenchymal Transition From Single-Cell Expression Atlas

Cancer, which refers to abnormal cell proliferative diseases with systematic pathogenic potential, is one of the leading threats to human health. The final causes for patients’ deaths are usually cancer recurrence, metastasis, and drug resistance against continuing therapy. Epithelial-to-mesenchymal transition (EMT), which is the transformation of tumor cells (TCs), is a prerequisite for pathogenic cancer recurrence, metastasis, and drug resistance. Conventional biomarkers can only define and recognize large tissues with obvious EMT markers but cannot accurately monitor detailed EMT processes. In this study, a systematic workflow was established integrating effective feature selection, multiple machine learning models [Random forest (RF), Support vector machine (SVM)], rule learning, and functional enrichment analyses to find new biomarkers and their functional implications for distinguishing single-cell isolated TCs with unique epithelial or mesenchymal markers using public single-cell expression profiling. Our discovered signatures may provide an effective and precise transcriptomic reference to monitor EMT progression at the single-cell level and contribute to the exploration of detailed tumorigenesis mechanisms during EMT.

Dissecting Efficacy and Metabolic Characteristic Mechanism of Taxifolin on Renal Fibrosis by Multivariate Approach and Ultra-Performance Liquid Chromatography Coupled With Mass Spectrometry-Based Metabolomics Strategy

Taxifolin (TFN) is an important natural compound with antifibrotic activity; however, its pharmacological mechanism is not clear. In this study, our aim is to gain insight into the effects of TFN and its potential mechanisms in unilateral ureteral obstruction (UUO) animal model using metabolomics approach to identify the metabolic biomarkers and perturbed pathways. Serum metabolomics analysis by UPLC-Q-TOF/MS was carried out to discover the changes in the metabolic profile. It showed that TFN has a significant protective effect on UUO-induced renal fibrosis and a total of 32 potential biomarkers were identified and related to RF progression. Of note, 27 biomarkers were regulated by TFN treatment, which participate in eight metabolic pathways, including phenylalanine, tyrosine and tryptophan biosynthesis, and phenylalanine metabolism. It also showed that metabolomics was a promising strategy to better dissect metabolic characteristics and pharmacological mechanisms of natural compounds by multivariate approach and ultra-performance liquid chromatography coupled with mass spectrometry.

Knockout of γ-Adducin Promotes NG-Nitro-L-Arginine-Methyl-Ester-Induced Hypertensive Renal Injury

Previous studies identified a region on chromosome 1 associated with N^G-nitro-L-arginine methyl ester (L-NAME) hypertension-induced renal disease in fawn-hooded hypertensive (FHH) rats. This region contains a mutant γ-adducin (Add3) gene that impairs renal blood flow (RBF) autoregulation, but its contribution to renal injury is unknown. The present study evaluated the hypothesis that knockout (KO) of Add3 impairs the renal vasoconstrictor response to the blockade of nitric oxide synthase and enhances hypertension-induced renal injury after chronic administration of L-NAME plus a high-salt diet. The acute hemodynamic effect of L-NAME and its chronic effects on hypertension and renal injury were compared in FHH 1^{Brown Norway} (FHH 1^BN) congenic rats (WT) expressing wild-type Add3 gene versus FHH 1^BN Add3 KO rats. RBF was well autoregulated in WT rats but impaired in Add3 KO rats. Acute administration of L-NAME (10 mg/kg) raised mean arterial pressure (MAP) similarly in both strains, but RBF and glomerular filtration rate (GFR) fell by 38% in WT versus 15% in Add3 KO rats. MAP increased similarly in both strains after chronic administration of L-NAME and a high-salt diet; however, proteinuria and renal injury were greater in Add3 KO rats than in WT rats. Surprisingly, RBF, GFR, and glomerular capillary pressure were 41%, 82%, and 13% higher in L-NAME-treated Add3 KO rats than in WT rats. Hypertensive Add3 KO rats exhibited greater loss of podocytes and glomerular nephrin expression and increased interstitial fibrosis than in WT rats. These findings indicate that loss of ADD3 promotes L-NAME-induced renal injury by altering renal hemodynamics and enhancing the transmission of pressure to glomeruli. SIGNIFICANCE STATEMENT: A mutation in the γ-adducin (Add3) gene in fawn-hooded hypertensive rats that impairs autoregulation of renal blood flow is in a region of rat chromosome 1 homologous to a locus on human chromosome 10 associated with diabetic nephropathy. The present results indicate that loss of ADD3 enhanced N^G-nitro-L-arginine methyl ester-induced hypertensive renal injury by altering the transmission of pressure to the glomerulus.

Boolean model of anchorage dependence and contact inhibition points to coordinated inhibition but semi-independent induction of proliferation and migration

Epithelial cells respond to their physical neighborhood with mechano-sensitive behaviors required for development and tissue maintenance. These include anchorage dependence, matrix stiffness-dependent proliferation, contact inhibition of proliferation and migration, and collective migration that balances cell crawling with the maintenance of cell junctions. While required for development and tissue repair, these coordinated responses to the microenvironment also contribute to cancer metastasis. Predictive models of the signaling networks that coordinate these behaviors are critical in controlling cell behavior to halt disease. Here we propose a Boolean regulatory network model that synthesizes mechanosensitive signaling that links anchorage to a matrix of varying stiffness and cell density sensing to contact inhibition, proliferation, migration, and apoptosis. Our model can reproduce anchorage dependence and anoikis, detachment-induced cytokinesis errors, the effect of matrix stiffness on proliferation, and contact inhibition of proliferation and migration by two mechanisms that converge on the YAP transcription factor. In addition, we offer testable predictions related to cell cycle-dependent anoikis sensitivity, the molecular requirements for abolishing contact inhibition, and substrate stiffness dependent expression of the catalytic subunit of PI3K. Moreover, our model predicts heterogeneity in migratory vs. non-migratory phenotypes in sub-confluent monolayers, and co-inhibition but semi-independent induction of proliferation vs. migration as a function of cell density and mitogenic stimulation. Our model serves as a stepping-stone towards modeling mechanosensitive routes to the epithelial to mesenchymal transition, capturing the effects of the mesenchymal state on anoikis resistance, and understanding the balance between migration versus proliferation at each stage of the epithelial to mesenchymal transition.

Semicarbazide-sensitive amine oxidase inhibition ameliorates albuminuria and glomerulosclerosis but does not improve tubulointerstitial fibrosis in diabetic nephropathy

Semicarbazide-sensitive amine oxidase (SSAO) is an enzyme with a unique dual function in controlling inflammation as well as reactive oxygen species (ROS) generation. We have demonstrated benefit of SSAO inhibition in acute kidney fibrosis. However the function of SSAO in chronic kidney disease (CKD) and diabetic kidney disease (DKD) is yet to be determined. We aimed to assess the effectiveness of a SSAO inhibitor (SSAOi; PXS-4728A) as an antifibrotic agent using a diabetic model of CKD. Diabetic mice were treated with SSAOi for 24 weeks and outcomes compared with untreated diabetic mice and telmisartan treated animals as a standard of care comparator. Extracellular matrix markers, fibronectin and oxidative stress, were downregulated in diabetic mice treated with SSAOi compared with untreated diabetic mice. Expression of the pan-leukocyte marker CD45 was also supressed by SSAOi. SSAO inhibition in diabetic mice resulted in a significant reduction in glomerulosclerosis and associated albuminuria compared to untreated diabetic mice. However, the effect of SSAO inhibition was less obvious in the tubulointerstitial compartment than in the glomeruli. Therefore, SSAO may be a potential target for diabetic glomerulosclerosis.

AXL targeting reduces fibrosis development in experimental unilateral ureteral obstruction

The AXL receptor tyrosine kinase (RTK) is involved in partial epithelial‐to‐mesenchymal transition (EMT) and inflammation – both main promoters of renal fibrosis development. The study aim was to investigate the role of AXL inhibition in kidney fibrosis due to unilateral ureteral obstruction (UUO). Eight weeks old male C57BL/6 mice underwent UUO and were treated with oral AXL inhibitor bemcentinib (n = 22), Angiotensin‐converting enzyme inhibitor (ACEI, n = 10), ACEI and bemcentinib (n = 10) or vehicle alone (n = 22). Mice were sacrificed after 7 or 15 days and kidney tissues were analyzed by immunohistochemistry (IHC), western blot, ELISA, Sirius Red (SR) staining, and hydroxyproline (Hyp) quantification. RNA was extracted from frozen kidney tissues and sequenced on an Illumina HiSeq4000 platform. After 15 days the ligated bemcentinib‐treated kidneys showed less fibrosis compared to the ligated vehicle‐treated kidneys in SR analyses and Hyp quantification. Reduced IHC staining for Vimentin (VIM) and alpha smooth muscle actin (αSMA), as well as reduced mRNA abundance of key regulators of fibrosis such as transforming growth factor (Tgfβ), matrix metalloproteinase 2 (Mmp2), Smad2, Smad4, myofibroblast activation (Aldh1a2, Crlf1), and EMT (Snai1,2, Twist), in ligated bemcentinib‐treated kidneys was compatible with reduced (partial) EMT induction. Furthermore, less F4/80 positive cells, less activity of pathways related to the immune system and lower abundance of MCP1, MCP3, MCP5, and TARC in ligated bemcentinib‐treated kidneys was compatible with reduction in inflammatory infiltrates by bemcentinib treatment. The AXL RTK pathway represents a promising target for pharmacologic therapy of kidney fibrosis.

The Role of NLRP3 Inflammasome Activation in the Epithelial to Mesenchymal Transition Process During the Fibrosis

Fibrosis is considered a complex form of tissue damage commonly present in the end stage of many diseases. It is also related to a high percentage of death, whose predominant characteristics are an excessive and abnormal deposition of fibroblasts and myofibroblasts -derived extracellular matrix (ECM) components. Epithelial-to-mesenchymal transition (EMT), a process in which epithelial cells gradually change to mesenchymal ones, is a major contributor in the pathogenesis of fibrosis. The key mediator of EMT is a multifunctional cytokine called transforming growth factor-β (TGF-β) that acts as the main inducer of the ECM assembly and remodeling through the phosphorylation of Smad2/3, which ultimately forms a complex with Smad4 and translocates into the nucleus. On the other hand, the bone morphogenic protein-7 (BMP-7), a member of the TGF family, reverses EMT by directly counteracting TGF-β induced Smad-dependent cell signaling. NLRP3 (NACHT, LRR, and PYD domains-containing protein 3), in turn, acts as cytosolic sensors of microbial and self-derived molecules and forms an immune complex called inflammasome in the context of inflammatory commitments. NLRP3 inflammasome assembly is triggered by extracellular ATP, reactive oxygen species (ROS), potassium efflux, calcium misbalance, and lysosome disruption. Due to its involvement in multiple diseases, NLRP3 has become one of the most studied pattern-recognition receptors (PRRs). Nevertheless, the role of NLRP3 in fibrosis development has not been completely elucidated. In this review, we described the relation of the previously mentioned fibrosis pathway with the NLRP3 inflammasome complex formation, especially EMT-related pathways. For now, it is suggested that the EMT happens independently from the oligomerization of the whole inflammasome complex, requiring just the presence of the NLRP3 receptor and the ASC protein to trigger the EMT events, and we will present different pieces of research that give controversial point of views.

LncRNA GAS5 attenuates fibroblast activation through inhibiting Smad3 signaling

Transforming growth factor-β (TGF-β)-induced fibroblast activation is a key pathological event during tissue fibrosis. Long noncoding RNA (lncRNA) is a class of versatile gene regulators participating in various cellular and molecular processes. However, the function of lncRNA in fibroblast activation is still poorly understood. In this study, we identified growth arrest-specific transcript 5 (GAS5) as a novel regulator for TGF-β-induced fibroblast activation. GAS5 expression was downregulated in cultured fibroblasts by TGF-β and in resident fibroblasts from bleomycin-treated skin tissues. Overexpression of GAS5 suppressed TGF-β-induced fibroblast to myofibroblast differentiation. Mechanistically, GAS5 directly bound mothers against decapentaplegic homolog 3 (Smad3) and promoted Smad3 binding to Protein phosphatase 1A (PPM1A), a Smad3 dephosphatase, and thus accelerated Smad3 dephosphorylation in TGF-β-treated fibroblasts. In addition, GAS5 inhibited fibroblast proliferation. Importantly, local delivery of GAS5 via adenoviral vector suppressed bleomycin-induced skin fibrosis in mice. Collectively, our data revealed that GAS5 suppresses fibroblast activation and fibrogenesis through inhibiting TGF-β/Smad3 signaling, which provides a rationale for an lncRNA-based therapy to treat fibrotic diseases.

Integrating the Polydopamine Nanosphere/Aptamers Nanoplatform with a DNase-I-Assisted Recycling Amplification Strategy for Simultaneous Detection of MMP-9 and MMP-2 during Renal Interstitial Fibrosis

Matrix metalloproteinase-9 (MMP-9) and matrix metalloproteinase-2 (MMP-2) play important roles in the progression of renal interstitial fibrosis (RIF). There is an increasing demand to construct a novel method for the simultaneous detection of MMP-9 and MMP-2 to monitor the progression of RIF. Herein, a strategy based on the nanoplatform composed of the polydopamine nanosphere and fluorescence-labeled aptamers is developed to simultaneously detect MMP-9 and MMP-2 with DNase-I-assisted recycling signal amplification. In the light of tracing the recovered fluorescence intensity at 520 and 610 nm upon adding MMP-9 and MMP-2, the increased fluorescence intensity is linear to the different concentrations of MMP-9 and MMP-2 with the detection limits of 9.6 and 25.6 pg/mL for MMP-9 and MMP-2, respectively. More intriguingly, the results of unilateral ureteral obstruction mice show that the concentration of MMP-9 in urine is increased with the extension of ligation time while the concentration of MMP-2 is reversed, indicating that the ratio of MMP-9 to MMP-2 could be considered as the potential urinary biomarker to evaluate the progress of RIF and the therapeutic effect of Huangkui capsule on RIF. Therefore, this study provides a paradigmatic strategy for the simultaneous detection of the dual markers of RIF, which is promising for the auxiliary clinical diagnosis and assessment of the prognosis of chronic kidney disease.

Extracellular Matrix in the Tumor Microenvironment and Its Impact on Cancer Therapy

Solid tumors are complex organ-like structures that consist not only of tumor cells but also of vasculature, extracellular matrix (ECM), stromal, and immune cells. Often, this tumor microenvironment (TME) comprises the larger part of the overall tumor mass. Like the other components of the TME, the ECM in solid tumors differs significantly from that in normal organs. Intratumoral signaling, transport mechanisms, metabolisms, oxygenation, and immunogenicity are strongly affected if not controlled by the ECM. Exerting this regulatory control, the ECM does not only influence malignancy and growth of the tumor but also its response toward therapy. Understanding the particularities of the ECM in solid tumor is necessary to develop approaches to interfere with its negative effect. In this review, we will also highlight the current understanding of the physical, cellular, and molecular mechanisms by which the pathological tumor ECM affects the efficiency of radio-, chemo-, and immunotherapy. Finally, we will discuss the various strategies to target and modify the tumor ECM and how they could be utilized to improve response to therapy.

Identification of the Perturbed Metabolic Pathways Associating With Renal Fibrosis and Evaluating Metabolome Changes of Pretreatment With Astragalus polysaccharide Through Liquid Chromatography Quadrupole Time-Of-Flight Mass Spectrometry

Renal fibrosis is glomerulosclerosis and renal tubulointerstitial fibrosis caused by the increase of interstitial cells and intercellular substances and the accumulation of extracellular matrix, and is a common pathological manifestation of renal disease progressing to end-stage renal failure. It has proved that Astragalus polysaccharide (AP) has curative effect on renal disease; however, its therapeutic mechanism on renal fibrosis is still unclear. Metabolomics approach provides an opportunity to identify novel molecular biomarkers. The purpose of this study is to study the changes of serum metabolic profile of rats with unilateral tubal ligation and replication of renal fibrosis model and the therapeutic effect of AP on it. The blood samples of rats in the control group, renal fibrosis model group, and AP treatment group collected on the 21st day were analyzed by metabolomics method based on UPLC-Q-TOF-MS. Principal component analysis (PCA) showed that clustering was obvious and significantly separated, and paired partial least squares discriminant analysis (OPLS-DA) was used for further analysis. Combined with the network databases such as HMDB and KEGG and a large number of literatures, 32 potential biomarkers related to renal fibrosis were preliminarily screened out and further verified by MS/MS secondary debris information. After pretreatment with AP, 20 biomarkers were significantly regulated, and correlated with phenylalanine, tyrosine, and tryptophan biosynthesis, phenylalanine metabolism, arachidonic acid metabolism, etc. It also revealed the metabolic changes of renal fibrosis and intervention effect of AP. These data uncover a link between metabolism and the molecular mechanism with potential implications in the understanding of the intervention effect of AP. Conclusively, UPLC-Q-TOF-MS-based metabolomics can be valuable and promising strategy to understand the disease mechanism and natural drug pretreatment.

Characterization of Macrophages and Myofibroblasts Appearing in Dibutyltin Dichloride-Induced Rat Pancreatic Fibrosis

Macrophages and myofibroblasts are important in fibrogenesis. The cellular characteristics in pancreatic fibrosis remain to be investigated. Pancreatic fibrosis was induced in F344 rats by a single intravenous injection of dibutyltin dichloride. Histopathologically, the induced pancreatic fibrosis was divided into 3 grades (1+, 2+, and 3+), based on collagen deposition. Immunohistochemically, CD68-expressing M1 macrophages increased with grade and CD163-expressing M2 macrophages also increased later than M1 macrophage appearance. Double immunofluorescence showed that there were macrophages coexpressing CD68 and CD163, suggesting a possible shift from M1 to M2 types; similarly, increased major histocompatibility complex class II- and CD204-expressing macrophages were polarized toward M1 and M2 types, respectively. These findings indicated the participation of M1- and M2-polarized macrophages. Mesenchymal cells staining positive for vimentin, desmin, and α-smooth muscle actin (α-SMA) increased with grade. There were mesenchymal cells coexpressing vimentin/α-SMA, desmin/α-SMA, and glial fibrillary acidic protein (GFAP)/α-SMA; Thy-1-expressing immature mesenchymal cells also increased in fibrotic lesions. Because α-SMA expression is a reliable marker for myofibroblasts, α-SMA-expressing pancreatic myofibroblasts might be originated from GFAP-expressing pancreatic stellate cells or Thy-1-expressing immature mesenchymal cells; the myofibroblasts could simultaneously express cytoskeletal proteins such as vimentin and desmin. The present findings would provide useful information for analyses based on features of macrophages and myofibroblasts in chemically induced pancreatic fibrosis.

Nrf2 signaling attenuates epithelial-to-mesenchymal transition and renal interstitial fibrosis via PI3K/Akt signaling pathways

BACKGROUND

Nrf2 constitutes a therapeutic reference point for renal fibrosis and chronic kidney diseases. Nrf2-related signaling pathways are recognized to temper endothelial-to-mesenchymal transition (EMT) in fibrotic tissue. Nevertheless, the mechanism by which Nrf2 mitigates renal interstitial fibrosis is imprecise.

METHODS

The relationship between Nrf2 and renal interstitial fibrosis was investigated using the unilateral ureteral obstruction (UUO) model of Nrf2^-/- mice. The mice were separated into four groups, based on the treatment and intervention: Nrf2^-/- + UUO, Nrf2^-/- + Sham, WT + UUO and WT + Sham. Histological examination of renal tissue following the hematoxylin-eosin and Masson staining was carried out, as well as immunohistochemical staining. Additionally, to confirm the in vivo discoveries, in vitro experiments with HK-2 cells were also performed.

RESULTS

The Nrf2^-/- + UUO group showed more severe renal interstitial fibrosis compared to the WT + UUO, Nrf2^-/- + Sham and WT + Sham groups. Furthermore, the manifestations of α-SMA and Fibronectin significantly increased, and the manifestation of E-cadherin considerably decreased in kidney tissues from the group of Nrf2^-/- + UUO, compared to the WT + UUO group. The Nrf2 protein level significantly decreased in HK-2 cells, in reaction to the TGF-β1 concentration. In addition, the overexpression of Nrf2 presented contradictory results. What is more, the PI3K/Akt signaling pathway was discovered to be activated in the proteins extracted from cultured cells, and treated with Nrf2 siRNA and kidney tissues from the Nrf2^-/- + UUO group.

CONCLUSIONS

The results we obtained demonstrate that Nrf2 signaling pathway may perhaps offset the development of EMT, prompted by TGF-β1 and renal interstitial fibrosis. Likewise, the anti-fibrotic effect of Nrf2 was imparted by the inactivation of PI3K/Akt signaling. From our discoveries, we deliver new insight related to the prevention and treatment of kidney fibrosis.

Co-expression analysis reveals dysregulated miRNAs and miRNA-mRNA interactions in the development of contrast-induced acute kidney injury

The pathogenesis of contrast-induced acute kidney injury (CI-AKI) is incompletely understood. MicroRNAs (miRNAs) are important mediators that normally function via post-transcriptional degradation of target mRNAs. Emerging evidence indicates the appearance of differentially expressed (DE) miRNAs in CI-AKI following the injection of intravenous contrast medium. However, there are differences in the pathological mechanism and incidence of CI-AKI between intravenous and intra-arterial contrast administration. The present study aimed to investigate the critical roles of dysregulated miRNAs and their associated mRNAs in kidney injury following intra-arterial contrast medium exposure. Based on a reliable CI-AKI rat model, we conducted genome-wide miRNA and mRNA expression profiling analysis using deep sequencing. In the study, 36 DE mature miRNAs were identified (fold change > 1.5 and p value < 0.05) in the kidneys of CI-AKI rats (n = 3) compared with that in the controls (n = 3), consisting of 23 up-regulated and 13 down-regulated DE miRNAs. Bioinformatic analysis revealed that wingnut (Wnt), transforming growth factor beta (TGF-β), and 5'-AMP-activated protein kinase (AMPK) signaling pathways were most likely to be modulated by these dysregulated miRNAs. Around 453 dysregulated genes (fold change > 2.0 and p value < 0.05) were identified. Integrated analysis revealed 2037 putative miRNA-mRNA pairs with negative correlations. Among them, 6 DE miRNAs and 13 genes were selected for further quantitative real-time reverse transcription polymerase chain reaction validation (n = 6 for each group), and a good correspondence between the two techniques was observed. In conclusion, the present study provided evidence of miRNA-mRNA interactions in the development of kidney injury following an intra-arterial contrast injection. These findings provide insights into the underlying mechanisms of CI-AKI.

Kangxianling decoction prevents renal fibrosis in rats with 5/6 nephrectomy and inhibits Ang II-induced ECM production in glomerular mesangial cells

Renal fibrosis is a common pathological change in all stages of kidney disease. Kangxianling decoction was widely used in patients with chronic kidney disease, which could improve symptoms such as poor appetite, edema, and fatigue. However, its effect on renal fibrosis remains to be studied. In this study, we investigated its effects on renal fibrosis in a rat model of 5/6 Nephrectomy (5/6 N) in vivo and in angiotensin II (Ang II)-treated rat glomerular mesangial cells (HBZY-1) in vitro. Our data showed that 5/6 N induced renal fibrosis and combined with the activation of JNK signaling, the upregulation of transforming growth factor-β (TGF-β), collagen I (Col-I) and fibronectin (FN). The administration of kangxianling decoction inhibited the activation of JNK signaling and attenuated the deposition of extracellular matrix (ECM) proteins in damaged kidneys. In HBZY-1 cells, Ang II increased the protein expression of Col-I and FN. It also activates JNK signaling and TGF-β in a time-dependent manner. Treatment of the HBZY-1 cells with kangxianling decoction blocked Ang II-induced JNK activation and ECM overproduction. Our results indicated that Kangxianling Decoction could reduce renal fibrosis, accompanied by inhibiting the production of ECM proteins and JNK, along with downregulation of TGF-β, Ang II.

Melatonin preconditioning of bone marrow-derived mesenchymal stem cells promotes their engraftment and improves renal regeneration in a rat model of chronic kidney disease

Bone marrow-derived mesenchymal stem cells (BMMSCs) transplantation has shown to be effective in treating chronic kidney disease. However, the effectiveness of this strategy is constrained by low homing and survival rate of transplanted cells in the injured organs. Therefore, developing strategies to improve homing and cell survival rate and therapeutic potential in cell-based therapies seems necessary. The purpose of this study is to evaluate the effect of pretreating BMMSCs with melatonin (MT) on the prosurvival and renoprotective of transplanted cells into the irreversible model of unilateral ureteral obstruction. Adult male Sprague-Dawley rats were randomized into four groups: Sham, UUO, UUO + BMMSCs, and UUO + BMMSCs + MT. The results of our study demonstrated that preconditioning with MT enhanced homing of BMMSCs into the injured kidney. MT reduced the number of TUNEL positive transplanted cells in the UUO + BMMSCs + MT group. The UUO + BMMSCs + MT group showed lower expressions of TGF-β1, α-SMA and TNF-α at both gene and protein levels but higher expression of E-cadherin compared with the UUO + BMMSCs group. In addition, MT preconditioned BMMSCs ameliorated basement membrane disruption and histological status of injured renal tubules and also reduced fibrosis in damaged kidneys. In conclusion, our results show that stem cells pretreated by MT may represent a feasible approach for improving the beneficial effects of stem cell therapy and significantly enhance their survival after transplantation to the injured kidney.

Blockade of ERK1/2 by U0126 alleviates uric acid-induced EMT and tubular cell injury in rats with hyperuricemic nephropathy

Extracellular signal-regulated kinases 1 and 2 (ERK1/2) are serine/threonine kinases and function as regulators of cellular proliferation and differentiation. Recently, we demonstrated that inhibition of ERK1/2 alleviates the development and progression of hyperuricemia nephropathy (HN). However, its potential roles in uric acid-induced tubular epithelial-mesenchymal transition (EMT) and tubular epithelial cell injury are unknown. In this study, we showed that hyperuricemic injury induced EMT as characterized by downregulation of E-cadherin and upregulation of vimentin and Snail1 in a rat model of HN. This was coincident with epithelial cells arrested at the G₂/M phase of cell cycle, activation of Notch1/Jagged-1 and Wnt/β-catenin signaling pathways, and upregulation of matrix metalloproteinase-2 (MMP-2) and MMP-9. Administration of U0126, a selective inhibitor of ERK1/2, blocked all these responses. U0126 was also effective in inhibiting renal tubular cell injury, as shown by decreased expression of lipocalin-2 and kidney injury molecule-1 and active forms of caspase-3. U0126 or ERK1/2 siRNA can inhibit tubular cell EMT and cell apoptosis as characterized with decreased expression of cleaved caspase-3. Moreover, ERK1/2 inhibition suppressed hyperuricemic injury-induced oxidative stress as indicated by decreased malondialdehyde and increased superoxide dismutase. Collectively, ERK1/2 inhibition-elicited renal protection is associated with inhibition of EMT through inactivation of multiple signaling pathways and matrix metalloproteinases, as well as attenuation of renal tubule injury by enhancing cellular resistance to oxidative stress.

Kidney decellularized extracellular matrix hydrogels: Rheological characterization and human glomerular endothelial cell response to encapsulation

Hydrogels, highly-hydrated crosslinked polymer networks, closely mimic the microenvironment of native extracellular matrix (ECM) and thus present as ideal platforms for three-dimensional cell culture. Hydrogels derived from tissue- and organ-specific decellularized ECM (dECM) may retain bioactive signaling cues from the native tissue or organ that could in turn modulate cell-material interactions and response. In this study, we demonstrate that porcine kidney dECM can be processed to form hydrogels suitable for cell culture and encapsulation studies. Scanning electron micrographs of hydrogels demonstrated a fibrous ultrastructure with interconnected pores, and rheological analysis revealed rapid gelation times with shear moduli dependent upon the protein concentration of the hydrogels. Conditionally-immortalized human glomerular endothelial cells (GEnCs) cultured on top of or encapsulated within hydrogels exhibited high cell viability and proliferation over a one-week culture period. However, gene expression analysis of GEnCs encapsulated within kidney dECM hydrogels revealed significantly lower expression of several relevant genes of interest compared to those encapsulated within hydrogels composed of only purified collagen I. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A:2448-2462, 2018.

Membrane rafts-redox signalling pathway contributes to renal fibrosis via modulation of the renal tubular epithelial-mesenchymal transition

KEY POINTS

Membrane rafts (MRs)-redox signalling pathway is activated in response to transforming growth factor-β1 (TGF-β1) stimulation in renal tubular cells. This pathway contributes to TGF-1β-induced epithelial-mesenchymal transition (EMT) in renal tubular cells. The the MRs-redox signalling pathway is activated in renal tubular cells isolated from angiotensin II (AngII)-induced hypertensive rats. Inhibition of this pathway attenuated renal inflammation and fibrosis in AngII-induced hypertension.

ABSTRACT

The membrane rafts (MRs)-redox pathway is characterized by NADPH oxidase subunit clustering and activation through lysosome fusion, V-type proton ATPase subunit E2 (encoded by the Atp6v1e2 gene) translocation and sphingomyelin phosphodiesterase 1 (SMPD1, encoded by the SMPD1 gene) activation. In the present study, we hypothesized that the MRs-redox-derived reactive oxygen species (ROS) are involved in renal inflammation and fibrosis by promoting renal tubular epithelial-mesenchymal transition (EMT). Results show that transforming growth factor-β1 (TGF-β1) acutely induced MR formation and ROS production in NRK-52E cells, a rat renal tubular cell line. In addition, transfection of Atp6v1e2 small hairpin RNAs (shRNA) and SMPD1 shRNA attenuated TGF-β1-induced changes in EMT markers, including E-cadherin, α-smooth muscle actin (α-SMA) and fibroblast-specific protein-1 (FSP-1) in NRK-52E cells. Moreover, Erk1/2 activation may be a downstream regulator of the MRs-redox-derived ROS, because both shRNAs significantly inhibited TGF-β1-induced Erk1/2 phosphorylation. Further in vivo study shows that the renal tubular the MRs-redox signalling pathway was activated in angiotensin II (AngII)-induced hypertension, as indicated by the increased NADPH oxidase subunit Nox4 fraction in the MR domain, SMPD1 activation and increased ROS content in isolated renal tubular cells. Finally, renal transfection of Atp6v1e2 shRNA and SMPD1 shRNA significantly prevented renal fibrosis and inflammation, as indicated by the decrease of α-SMA, fibronectin, collagen I, monocyte chemoattractant protein-1 (MCP-1), intercellular cell adhesion molecule-1 (ICAM-1) and tumour necrosis factor-α (TNF-α) in kidneys from AngII-infused rats. It was concluded that the the MRs-redox signalling pathway is involved in TGF-β1-induced renal tubular EMT and renal inflammation/fibrosis in AngII-induced hypertension.

Rab7 empowers renal tubular epithelial cells with autophagy-mediated protection against albumin-induced injury

Most patients with chronic kidney disease (CKD) present with proteinuria and extracellular matrix (ECM) deposition in the interstitium. Matrix metalloproteinase-2 (MMP-2) is important for maintaining ECM metabolism and it affects the formation and development of CKD. Autophagy has been reported to be protective against renal tubular injury, but the role of autophagy related to ECM metabolism is unclear. Rab7 is a shared molecule of endocytosis and autophagy. The aim of this study is to explore the role of autophagy in regulating MMP-2 activity and to determine whether Rab7 functions in regulating MMP-2 activity and injury in albumin-overloaded TECs. In this study, abovine serum albumin (BSA)-overload rat model was first established and collagen deposition and deficient autophagic response were observed in vivo, and stimulation with albumin nanoparticles resulted in MMP-2 overactivation and obstructed autophagic flux induced by lysosomal dysfunction in vitro. Furthermore, overactivation of MMP-2 was mediated by its related regulatory molecules such as membrane-type 1 MMP (MT1-MMP), tissue inhibitor of metalloproteinase-2 (TIMP-2) and reversion-inducing-cysteine-rich protein with kazal motifs (RECK) on the membrane of TECs (HK-2 cellline). After up-regulating Rab7, albumin-induced MMP-2 overactivation was attenuated, which was reversed by chloroquine (CQ; an endocytosis inhibitor). In addition, our data indicated that up-regulation of Rab7 relieved epithelial-mesenchymal transition (EMT) and apoptosis in albumin-treated TECs. Taken together, our study demonstrated that autophagy regulates MMP-2 activity in a Rab7-dependent manner. Thus, Rab7 is a newly developed target for protecting TECs from albumin-induced injury.

Serum 6-Bromotryptophan Levels Identified as a Risk Factor for CKD Progression

Background Metabolite levels reflect physiologic homeostasis and may serve as biomarkers of disease progression. Identifying metabolites associated with APOL1 risk alleles-genetic variants associated with CKD risk commonly present in persons of African descent-may reveal novel markers of CKD progression relevant to other populations.Methods We evaluated associations between the number of APOL1 risk alleles and 760 serum metabolites identified via untargeted profiling in participants of the African American Study of Kidney Disease and Hypertension (AASK) (n=588; Bonferroni significance threshold P<6.5×10^-5) and replicated findings in 678 black participants with CKD in BioMe, an electronic medical record-linked biobank. We tested the metabolite association with CKD progression in AASK, BioMe, and the Modification of Diet in Renal Disease (MDRD) Study.Results One metabolite, 6-bromotryptophan, was significant in AASK (P=4.7×10^-5) and replicated in BioMe (P=5.7×10^-3) participants, with lower levels associated with more APOL1 risk alleles. Lower levels of 6-bromotryptophan were associated with CKD progression in AASK and BioMe participants and in white participants in the MDRD Study, independent of demographics and clinical characteristics, including baseline GFR (adjusted hazard ratio per two-fold higher 6-bromotryptophan level, AASK, 0.76; 95% confidence interval [95% CI], 0.64 to 0.91; BioMe, 0.61; 95% CI, 0.43 to 0.85; MDRD, 0.52; 95% CI, 0.34 to 0.79). The interaction between the APOL1 risk alleles and 6-bromotryptophan was not significant. The identity of 6-bromotryptophan was confirmed in experiments comparing its molecular signature with that of authentic standards of other bromotryptophan isomers.Conclusions Serum 6-bromotryptophan is a consistent and novel risk factor for CKD progression.

Diacerein alleviates kidney injury through attenuating inflammation and oxidative stress in obese insulin-resistant rats

A link between inflammation with obesity and metabolic syndrome has been found in patients with chronic kidney disease (CKD). Diacerein is an anthraquinone used to treat osteoarthritis that exerts anti-inflammatory action by inhibiting the synthesis and activity of proinflammatory cytokines. This study aimed to investigate the protective effect of diacerein on renal function and renal organic anion transporter 3 (Oat3) function in obese insulin-resistant condition. Obese insulin-resistant rats were induced by feeding a high-fat diet in male Wistar rats for 16 weeks. Diacerein or metformin (positive control) (30mg/kg/day) was administered orally for 4 weeks after insulin resistance had been confirmed. Obese insulin-resistant rats showed an impaired renal function as indicated by the increased serum creatinine and microalbuminuria along with the decreased renal Oat3 function and expression. Importantly, diacerein treatment not only improved insulin resistance but also restored renal function. The decreased renal malondialdehyde level, expressions of PKCα, angiotensin 1 receptor (AT1R), Nrf2, and HO-1, and increased expression of SOD2 were observed in diacerein treatment group, indicating the attenuation of renal oxidative stress condition. Moreover, renal inflammation and renal damage were also alleviated in diacerein-treated rats. Our results demonstrated for the first time that diacerein was effective to improve renal function and renal Oat3 function in obese insulin-resistance condition mediated by suppressing renal oxidative stress and inflammation. These findings suggest that anti-inflammatory agents can be used therapeutically to improve metabolic disorder and prevent organ dysfunctions in pre-diabetic condition.

Epithelial contribution to the profibrotic stiff microenvironment and myofibroblast population in lung fibrosis

The contribution of epithelial-to-mesenchymal transition (EMT) to the profibrotic stiff microenvironment and myofibroblast accumulation in pulmonary fibrosis remains unclear. We examined EMT-competent lung epithelial cells and lung fibroblasts from control (fibrosis-free) donors or patients with idiopathic pulmonary fibrosis (IPF), which is a very aggressive fibrotic disorder. Cells were cultured on profibrotic conditions including stiff substrata and TGF-β1, and analyzed in terms of morphology, stiffness, and expression of EMT/myofibroblast markers and fibrillar collagens. All fibroblasts acquired a robust myofibroblast phenotype on TGF-β1 stimulation. Yet IPF myofibroblasts exhibited higher stiffness and expression of fibrillar collagens than control fibroblasts, concomitantly with enhanced FAKY397 activity. FAK inhibition was sufficient to decrease fibroblast stiffness and collagen expression, supporting that FAKY397 hyperactivation may underlie the aberrant mechanobiology of IPF fibroblasts. In contrast, cells undergoing EMT failed to reach the values exhibited by IPF myofibroblasts in all parameters examined. Likewise, EMT could be distinguished from nonactivated control fibroblasts, suggesting that EMT does not elicit myofibroblast precursors either. Our data suggest that EMT does not contribute directly to the myofibroblast population, and may contribute to the stiff fibrotic microenvironment through their own stiffness but not their collagen expression. Our results also support that targeting FAKY397 may rescue normal mechanobiology in IPF.

Usefulness of urinary collagen IV excretion for predicting the severity of Henoch-Schönlein nephropathy children

The aim of the study

The aim of the study was to evaluate the usefulness of urinary collagen IV (Col IV) excretion for predicting the severity of autoimmune renal inflammation in children with HSN (Henoch-Schönlein nephritis).

Material and methods

We studied 26 children, in whom HSN was diagnosed based on kidney biopsy. In all patients, urinalysis was performed and 24-hour urinary protein excretion was measured at the onset of the disease. All kidney biopsies were also scored using the Oxford classification: M – mesangial hypercellularity score (M0 absent, M1 present); E – presence of endocapillary proliferation (E0 absent, E1 present), S – segmental glomerulosclerosis/adhesion (S0 absent, S1 present), T – tubular atrophy/interstitial fibrosis (T0 ≤ 25%, T1 26-50%, T2 > 50%). The MEST score was calculated as the sum of M + E + S + T.

Results

Urinary Col IV level was significantly higher in the study group than in control group. Urinary Col IV level was insignificantly higher in group A (nephrotic proteinuria) compared to the B (non-nephrotic proteinuria) and C (without proteinuria).We found no significant differences in the age at the disease onset, severity of proteinuria, and Col IV between groups 1 (S0, T0) and 2.(S1,T1/T2). The MEST score was significantly higher in group 2 than group 1.

Conclusions

Urinary Col IV excretion in children with HSN may be related to the lesions severity by the Oxford classification but seems to be associated with the mean value (the MEST score).

In younger children, a more aggressive disease course is observed, and thus earlier and more aggressive treatment should be considered in this group.

Impaired erythropoietin synthesis in chronic kidney disease is caused by alterations in extracellular matrix composition

Renal fibrosis and anaemia are two of the most relevant events in chronic kidney disease. Fibrosis is characterized by the accumulation of extracellular matrix proteins in the glomeruli and tubular interstitium. Anaemia is the consequence of a decrease in erythropoietin production in fibrotic kidneys. This work analyses the possibility that the accumulation of abnormal collagens in kidney interstitium could be one of the mechanisms responsible for erythropoietin decreased synthesis. In renal interstitial fibroblast grown on collagen I, erythropoietin mRNA expression and HIF‐2α protein decreased, whereas focal adhesion kinase protein (FAK) phosphorylation and proteasome activity increased, compared to cells grown on collagen IV. Proteasome inhibition or FAK inactivation in cells plated on collagen I restored erythropoietin and HIF‐2α expression. FAK inhibition also decreased the collagen I‐dependent proteasome activation. In a model of tubulointerstitial fibrosis induced by unilateral ureteral obstruction in mice, increased collagen I protein content and an almost complete disappearance of erythropoietin mRNA expression were observed in the ureteral ligated kidney with respect to the contralateral control. Interestingly, erythropoietin synthesis was recovered in obstructed mice treated with proteasome inhibitor. These data suggest that reduced kidney erythropoietin synthesis could be caused by the accumulation of abnormal extracellular matrix proteins.

Renal protective effect and action mechanism of Huangkui capsule and its main five flavonoids

ETHNOPHARMACOLOGICAL RELEVANCE

The flower of Abelmoschus manihot (Linn.) Medicus (A. manihot), as a traditional Chinese Herbal medicine, was used widely in China with efficacy of inducing diuresis for treating strangurtia, and subdhing swelling and detoxicating. It has been reported that Huangkui capsule, prepared by the extract of the flower of A. manihot, can reduce the content of urinary protein, serum creatinine and serum urea nitrogen in nephropathy rats and processes renoprotective activity, while the action mechanism need to illuminate deeply.

AIMS OF THE STUDY

In this study, we investigated the protection effect of Huangkui capsule on tubulointerstitial fibrosis in chronic renal failure (CRF) rats and its mechanism against high glucose-induced epithelial to mesenchymal transition (EMT) in renal tubular epithelial cells (HK-2) of its bioactive components.

MATERIALS AND METHODS

The animals were divided into normal group, CRF model group and Huangkui capsule-treated group. Hematoxylin eosin (HE) staining and Masson staining were applied to observe pathological changes in renal tissue of different groups. Biochemical indicators including serum urea nitrogen (BUN), urine protein (UP) and serum creatinine (Scr) were measured according to the manufacturer's instructions of kits. HK-2 cell damaged model was established to access the protection effect and action mechanism of five main flavonoids from Huangkui capsule. The experimental cells were divided into eight groups: control group, model group, positive drug group and five main flavonoids treated groups. The dichlorodihydrofluorescein diacetate (DCFH-DA) assay was used to determine the reactive oxygen species (ROS) in different groups. Western blot was applied to analyze the expression of pathogenesis-related proteins in different groups.

RESULTS

The results stated that Huangkui capsule significantly inhibited the elevation of Scr, BUN, UP, the expression of α-smooth muscle actin (α-SMA), phosphorylation-extracellular signal-regulated kinase (p-ERK1/2), NADPH Oxidase 1, NADPH Oxidase 2 and NADPH Oxidase 4 in adenine-induced CRF rats. The main bioactive components of quercetin (QT), hyperoside (HY), isoquercitrin (IQT), gossypetin-8-O-β-D-glucuronide (GG) and quercetin-3'-O-glucoside (QG) at the dosage of 100µM, like NADPH oxidase inhibitor diphenyleneiodonium, exhibited a significant effect on inhibiting the expression of α-SMA, p-ERK1/2, NADPH Oxidase 1, NADPH Oxidase 2 and NADPH Oxidase 4 in high glucose-induced HK-2 cells, especially GG.

CONCLUSIONS

These results demonstrated that Huangkui capsule and the flavonoids components prevent tubulointerstitial fibrosis in CRF rat involvement in the action mechanism of inhibiting NADPH oxidase/ROS/ERK pathway.

Flucytosine and Amphotericin B Coadministration Induces Dose-Related Renal Injury

Invasive fungal infections remain an important clinical problem, and despite recent approaches, they bring high morbidity and mortality. Combination therapies are the most effective; however, adverse effects need to be considered. In this study, we aimed to evaluate the nephrotoxicity induced by combined therapy of flucytosine (FL) and amphotericin B (AMF) at 3 different doses administered to mice for 14 days: 300 μg/kg AMF+50 mg/kg FL; 600 μg/kg AMF+100 mg/kg FL; 900 μg/kg AMF+150 mg/kg FL. Antifungal coadministration triggered nuclear translocation of NF-κB and upregulated nuclear factor kappa-light-chain-enhancer of activated B cells subunit p65 (NF-κB p65) messenger RNA mRNA level in dose-dependent manner. The immunopositivity of tumor necrosis factor-α and interleukin-6 (IL-6), together with IL-6 gene expression, increased both in tubular and glomerular cells. Amphotericin B–flucytosine cotreatment increased significantly the number of terminal deoxy-nucleotidyl transferase (TdT)-mediated dUTP nick end-labeling positive nuclei. Apoptotic cells in renal tubuli were confirmed by electron microscopy. Histopathological analysis revealed collagen accumulation at the glomerular level. Collagen was also evidenced in the glomeruli at the dose of 900 μg/kg AMF+150mg/kg FL by Masson-Goldner trichrome staining and electron microscopy. Moreover, antifungal cotherapy induced upregulation of transforming growth factor beta 1 (TGF-β1) gene expression in a dose-dependent manner. Inflammation and epithelial tubular apoptosis are associated with TGF-β1 activation and initiation of the early stage of glomerular fibrosis at higher doses, leading to tubule–interstitial fibrosis.

Alpha-lipoic acid ameliorates the epithelial mesenchymal transition induced by unilateral ureteral obstruction in mice

The epithelial-to-mesenchymal transition (EMT) is one of mechanisms that induce renal interstitial fibrosis. Understanding EMT in renal fibrosis has important therapeutic implications for patients with kidney disease. Alpha-lipoic acid (ALA) is a natural compound with antioxidant properties. Studies for ALA are performed in acute kidney injury with renal tubular apoptosis, renal inflammation, and oxidative stress. We investigated the effects of ALA on EMT-mediated renal interstitial fibrosis in mice with unilateral ureteral obstruction (UUO). UUO mice developed severe tubular atrophy and tubulointerstitial fibrosis, with a robust EMT response and ECM deposition after 7 postoperative days. In contrast, ALA-treated UUO mice showed only moderate injury and minimal fibrosis and also larger reductions in the expression of ECM proteins, inflammatory factors, and EMT markers. ALA was shown to be involved in the suppression of infiltrating macrophages associated with EMT and the progression of interstitial fibrosis. It also lessened the destruction of the tubular basement membrane, by reducing the expression of matrix metalloproteinases. This is the first study to show that ALA modulates EMT in a UUO mouse model. Our results suggest that ALA merits further exploration as a therapeutic agent in the prevention and treatment of chronic kidney disease.

Novel Therapeutics Identification for Fibrosis in Renal Allograft Using Integrative Informatics Approach

Chronic allograft damage, defined by interstitial fibrosis and tubular atrophy (IF/TA), is a leading cause of allograft failure. Few effective therapeutic options are available to prevent the progression of IF/TA. We applied a meta-analysis approach on IF/TA molecular datasets in Gene Expression Omnibus to identify a robust 85-gene signature, which was used for computational drug repurposing analysis. Among the top ranked compounds predicted to be therapeutic for IF/TA were azathioprine, a drug to prevent acute rejection in renal transplantation, and kaempferol and esculetin, two drugs not previously described to have efficacy for IF/TA. We experimentally validated the anti-fibrosis effects of kaempferol and esculetin using renal tubular cells in vitro and in vivo in a mouse Unilateral Ureteric Obstruction (UUO) model. Kaempferol significantly attenuated TGF-β1-mediated profibrotic pathways in vitro and in vivo, while esculetin significantly inhibited Wnt/β-catenin pathway in vitro and in vivo. Histology confirmed significantly abrogated fibrosis by kaempferol and esculetin in vivo. We developed an integrative computational framework to identify kaempferol and esculetin as putatively novel therapies for IF/TA and provided experimental evidence for their therapeutic activities in vitro and in vivo using preclinical models. The findings suggest that both drugs might serve as therapeutic options for IF/TA.