Glomerular Endothelial Cell Injury Research Articles

ITreg cells-secreted IL10 alleviates lupus nephritis through inactivating lncRNA HAR1A transcription to suppress SMARCD1-mediated iNOS activation

Lupus nephritis (LN) is a highly prevalent complication of systemic lupus erythematosus (SLE). Long non-coding RNAs (lncRNAs) are essential modulators in multiple types of human diseases, including LN. In the current study, we searched on online GEO database to select out lncRNAs that were differentially expressed in blood samples of LN patients. Through further RT-qPCR analysis, we found that lncRNA Highly Accelerated Region 1 A (HAR1A) is most significantly upregulated in blood samples of LN patients. Functionally, we detected that overexpression of HAR1A could aggravate LPS-induced injury and inflammation. According to the results of bioinformatics analysis and mechanism experiments, we determined that HAR1A binds with miR-149-3p to upregulate SMARCD1 through competing endogenous RNA (ceRNA) mechanism. It has been proven that iNOS is an inflammation inducer. Here, we found that HAR1A/miR-149-3p/SMARCD1 upregulates iNOS expression through enhancing H3K27ac level in iNOS promoter. Previously, we proved that CD8+CD103+ iTreg cells could alleviate glomerular endothelial cell injury. Moreover, we demonstrated that CD8 + CD103+ iTreg cells-secreted IL-10 downregulated HAR1A expression by impeding NF-κB pathway activation. In conclusion, this study provides evidences revealing a novel molecular pathway blocked by CD8+CD103+ iTreg cells in LN.

Targeting KLF2 as a Novel Therapy for Glomerular Endothelial Cell Injury in Diabetic Kidney Disease.

DKD is a microvascular disease, and glomerular endothelial cell injury is a key pathological event in DKD development. Through unbiased screening of glomerular transcriptomes, we previously identified KLF2 as a highly regulated gene in diabetic kidneys. KLF2 exhibits protective effects in endothelial cells by inhibiting inflammation, thrombotic activation, and angiogenesis, all of which are protective for cardiovascular disease. We previously demonstrated that endothelial cell-specific ablation of Klf2 exacerbated diabetes-induced glomerular endothelial cell injury and DKD in mice. Therefore in this study, we sought to assess the therapeutic potential of KLF2 activation in murine models of DKD. We first examined the effects of endothelial cell-specific inducible overexpression of KLF2 (KLF2ov) in streptozotocin-induced diabetic mice. We developed small molecule KLF2 activators and tested whether increased KLF2 activity could impede DKD progression in type 2 diabetic db/db and BTBR ob/ob mice. Diabetic KLF2ov mice had attenuated albuminuria, glomerular endothelial cell injury, and diabetic glomerulopathy compared to control diabetic mice. Novel KLF2 activator, compound 6 (C-6) effectively induced downstream Nos3 expression and suppressed NF-kB activation in glomerular endothelial cells. The administration of C-6 improved albuminuria and glomerulopathy in db/db and BTBR ob/ob mice, which was associated with improved glomerular endothelial cell and podocyte injury. These results validate KLF2 as a potential drug target and KLF2 activators such as C-6 as a novel therapy for DKD.

Nogo-B May Mediate the Glomerular Endothelial Cell Injury of Hypertensive Nephropathy by Enhancing the Inflammatory Phenotype

Nogo-B May Mediate the Glomerular Endothelial Cell Injury of Hypertensive Nephropathy by Enhancing the Inflammatory Phenotype

#1071 The effect and mechanism of SGLT2 inhibitor on improving inflammatory injury of glomerular endothelial cells in diabetes

Abstract Background and Aims ATP-binding cassette transporter A1 (ABCA1), which reduces intracellular cholesterol accumulation, is highly expressed in the kidney. Studies have shown that sodium-glucose co-transporter 2 inhibitors (SGLT2) inhibitors promote ABCA1 expression in multiple tissues and organs. However, the effect of SGLT2 inhibitors on ABCA1 expression in diabetic kidney disease (DKD) is unclear. In this study, the effect of empagliflozin, an SGLT2 inhibitor, on ABCA1 in glomerular endothelial cells(GECs) of DKD and the possible mechanisms linking ABCA1 to GECs inflammatory injury were investigated. Method Kidney tissues were obtained from renal biopsies of patients with early and advanced DKD. db/db mice were used as animal models of type 2 diabetes and the effects of SGLT2 inhibitors on ABCA1 were analyzed by treatment with empagliflozin. The effects of ABCA1 overexpression on glomerular lipid deposition and kidney injury were examined in a type 2 diabetic mouse model with ABCA1 overexpression (db/db + ABCA1 mice), and human renal glomerular endothelial cells (HRGECs) cultured in high glucose and high cholesterol conditions, which simulated type 2 diabetes in vitro. Results The expression of ABCA1 in the glomeruli of DKD patients and db/db mice was significantly decreased. Enhancing ABCA1 expression in the kidney tissue of diabetic mice by adenovirus transduction improved renal cholesterol deposition, inhibited the overactivation of C3a/C5a, and improved renal inflammatory injury. In addition, in cultured HRGECs under high glucose and high cholesterol conditions, ABCA1 deficiency increased the deposit of cellular cholesterol, contributed to overactivation of C3a/C5a, and induced inflammatory injury. Overexpression of ABCA1 enhancing cholesterol efflux or inhibition of C3a/C5a activation in vitro significantly protected against glomerular endothelial injury stimulated by high glucose and high cholesterol. Moreover, SGLT2 inhibitor empagliflozin up-regulated the expression of ABCA1 and down-regulated the levels of cholesterol, C3a/C5a and inflammatory cytokines in diabetic mice and HRGECs. Conclusion SGLT2 inhibitor (empagliflozin) might play a renal protective role by up-regulating ABCA1-mediated cholesterol outflow, inhibiting the activation of C3a/C5a, and then ameliorating the inflammatory injury of GECs.

Panax Notoginseng Saponins Alleviate High Glucose-Induced Glomerular Endothelial Cell Injury by Inhibiting the ET-1/PKC/TGF-β1 Signaling Pathway

This study aimed to investigate the protective effects and underlying mechanisms of Panax notoginseng saponins (PNS) on glomerular endothelial cell (GEC) injury induced by high glucose, which is crucial in the development of diabetic nephropathy. GECs were treated with high glucose alone, PNS alone, or a combination of PNS and overexpression of endothelin-1 (ET-1), a key regulator in endothelial dysfunction. The results showed that high glucose inhibited cell viability, increased reactive oxygen species (ROS) levels, and upregulated the expression of fibronectin (FN), collagen type IV (Col-IV), protein kinase C (PKC), transforming growth factor-beta 1 (TGF-β1), and ET-1. Additionally, high glucose downregulated the expression of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT). PNS treatment significantly protected against high glucose-induced GEC injury by promoting cell viability, reducing ROS generation, downregulating FN, Col-IV, PKC, TGF-β1, and ET-1 expression, and upregulating SOD, GSH-Px, and CAT expression. However, ET-1 overexpression reversed the protective effects of PNS, indicating the involvement of the ET-1/protein kinase C (PKC)/TGF-β1 pathway. In conclusion, PNS demonstrated a protective effect against high glucose-induced GEC injury by inhibiting the ET-1/PKC/TGF-β1 pathway. These findings suggest that PNS may be a potential therapeutic target for diabetic nephropathy by antagonizing ET-1.

Soluble Urokinase Plasminogen Activator Receptor Contributes to ANCA-positive IgG-mediated Glomerular Endothelial Activation through TLR4 Pathway.

The soluble urokinase plasminogen activator receptor (suPAR), a biomarker of inflammation, has been found to be a potential prognostic factor of renal function progression. Our previous study showed that plasma suPAR levels were significantly associated with disease activity and prognosis in patients with antineutrophil cytoplasmic autoantibody-associated vasculitis (AAV). This study aimed to explore whether urokinase plasminogen activator receptor (uPAR) participated in MPO-ANCA-induced glomerular endothelial cell (GEnC) injury, which is one of the most important aspects in the pathogenesis of AAV. GEnC activation and injury were analyzed by measuring the mRNA levels of ICAM-1 and VCAM-1. Permeability experiments were performed to detect endothelial monolayer activation in number. The expression of TLR4 was detected. In addition, TLR4 siRNA and TLR4 inhibitors were employed to determine its role. Bioinformatics methods were used for further analysis. Compared with a single stimulation, uPAR could further increase the expression of ICAM-1 and VCAM-1 mRNA levels, increase endothelial monolayer permeability and impair tight junctions in GEnCs stimulated with MPO-ANCA-positive IgG. The expression of TLR4 was upregulated by uPAR and MPO-ANCApositive IgG stimulation. TLR4 siRNA significantly reduced the expression of ICAM-1 and VCAM-1 mRNA levels induced by uPAR and MPO-ANCA-positive IgG. The TLR4 antagonist significantly downregulated the levels of ICAM-1 mRNA in cells and sICAM-1 in the supernatants of GEnCs treated with uPAR plus MPOANCA- positive IgG. PLAUR is a core gene in bioinformatics analysis. uPAR protein can enhance the GEnC activation and injury induced by MPO-ANCA-positive IgG through the TLR4 pathway, indicating that suPAR may be involved in the pathogenesis of AAV and that su- PAR might be regarded as a potential therapeutic target.

KITLG Promotes Glomerular Endothelial Cell Injury in Diabetic Nephropathy by an Autocrine Effect.

Diabetic nephropathy (DN) is an increasing threat to human health. The impact of hyperglycemia or its metabolites, advanced glycation end-products (AGEs), on glomerular endothelial cells (GECs) and their pathophysiologic mechanisms are not well explored. Our results reveal that AGEs increased the expression and secretion of the KIT ligand (KITLG) in GECs. Both AGEs and KITLG promoted endothelial-to-mesenchymal transition (EndoMT) in GECs and further increased the permeability of GECs through the AKT/extracellular-signal-regulated kinase pathway. Inhibition of KITLG’s effects by imatinib prevented AGE-medicated EndoMT in GECs, supporting the belief that KITLG is a critical factor for GEC injury. We found higher KITLG levels in the GECs and urine of db/db mice compared with db/m mice, and urinary KITLG levels were positively correlated with the urinary albumin-to-creatinine ratio (ACR). Furthermore, type 2 diabetic patients had higher urinary KITLG levels than normal individuals, as well as urinary KITLG levels that were positively correlated with urinary ACR and negatively correlated with the estimated glomerular filtration rate. KITLG plays a pathogenic role in GEC injury in DN and might act as a biomarker of DN progression.

Retraction to: CD8+CD103+ iTregs inhibit the progression of lupus nephritis by attenuating glomerular endothelial cell injury.

Retraction to: CD8+CD103+ iTregs inhibit the progression of lupus nephritis by attenuating glomerular endothelial cell injury.

Interleukin-6 Downregulates the Expression of Vascular Endothelial-Cadherin and Increases Permeability in Renal Glomerular Endothelial Cells via the Trans-Signaling Pathway

The pathogenesis of IgA nephropathy (IgAN) is still unknown, but reportedly, interleukin 6 (IL-6) is involved in this process. However, its role in damaging glomerular endothelial cells is still unclear. Therefore, in this study, to clarify the mechanism of the pathogenesis of IgAN, we investigated the effect of IL-6 on the permeability of glomerular endothelial cells. A rat model of IgAN was established, and the animals divided into two groups, namely, the normal and IgAN groups. Glomerular endothelial cell injury was evaluated via electron microscopy. Furthermore, IL-6-induced changes in the permeability of human renal glomerular endothelial cells (HRGECs) were measured via trans-endothelial resistance (TEER) measurements and fluorescein isothiocyanate-dextran fluorescence. Furthermore, vascular endothelial-cadherin (VE-cadherin) was overexpressed to clarify the effect of IL-6 on HRGEC permeability, and to determine the pathway by which it acts. The classical signaling pathway was blocked by silencing IL-6R and the trans-signaling pathway was blocked by sgp30Fc. In IgAN rats, electron microscopy showed glomerular endothelial cell damage and western blotting revealed a significant increase in IL-6 expression, while VE-cadherin expression decreased significantly in the renal tissues. IL-6/IL-6R stimulation also significantly increased the permeability of HRGECs (p < 0.05). This effect was significantly reduced by VE-cadherin overexpression (p < 0.01). After IL-6R was silenced, IL-6/IL-6R still significantly reduced VE-cadherin expression and sgp30Fc blocked the trans-signaling pathway as well as the upregulation of IL-6/IL-6R-induced VE-cadherin expression. This suggests that IL-6 mainly acts via the trans-signaling pathway. IL-6 increased the permeability of HRGECs by decreasing the expression of VE-cadherin via the trans-signaling pathway.

Glomerular deposition of galactose-deficient IgA1-containing immune complexes via glomerular endothelial cell injuries.

ABSTRACTBackgroundGalactose-deficient immunoglobulin A1 (Gd-IgA1) plays a crucial role in the development of IgA nephropathy (IgAN). However, the pathological role of Gd-IgA1-containing immune complexes (ICs) and the mechanism of deposition in the mesangial region remain unclear.MethodsTo examine the deposition of Gd-IgA1-containing ICs in the mesangial region through glomerular endothelial cell injury, we evaluated the alteration of renal microvascular endothelial glycocalyx in nude mice injected with Gd-IgA1-IgG ICs. Human renal glomerular endothelial cells (HRGECs) were used to assess the potential capacity of Gd-IgA1-IgG ICs to activate endothelial cells.ResultsNude mice injected with Gd-IgA1-containing ICs showed podocyte and endothelial cell injuries, with IgA, IgG and C3 depositions in glomerular capillaries and the mesangium. Moreover, albuminuria and hematuria were induced. Real-time glycocalyx imaging showed that renal microvascular glycocalyx was decreased immediately after injection of Gd-IgA1-containing ICs and then mesangial IgA deposition was increased. After coculture of Gd-IgA1-containing ICs with HRGECs, messenger RNA expression levels of endothelial adhesion molecules and proinflammatory mediators were upregulated significantly.ConclusionGd-IgA1-IgG ICs had a high affinity for glomerular endothelial cells, which resulted in glomerular filtration barrier dysfunction mediated by glycocalyx loss. Furthermore, Gd-IgA1-IgG ICs accelerated the production of adhesion factors and proinflammatory cytokines in glomerular endothelial cells. The glomerular endothelial cell injury induced by Gd-IgA1-containing ICs may enhance the permeability of Igs in the mesangial region and subsequent inflammatory responses in the pathogenesis of IgAN.

Endothelin-1 down-regulated vascular endothelial growth factor A is involved in trichloroethene-induced kidney injury.

The mechanism of kidney injury in occupational medicamentosa-like dermatitis due to trichloroethylene exposure is not well understood. This study aimed to investigate the role of endothelin-1 (ET-1)/vascular endothelial-derived growth factor-A (VEGF-A) in trichloroethylene (TCE)-induced renal injury. Forty BALB/c female mice were used in this study to build the TCE-sensitization mouse model. Transmission electron microscopic observation, histological examination, periodic acid-Schiff staining, serum urea nitrogen, creatinine, and urinary total protein levels were used to reflect renal injury. Glypican1, syndecan1, ET-1 and VEGF-A protein levels were measured by western blot. Serum ET-1 level was also measured. Tumor necrosis factor alpha (TNF-α) and vascular cell adhesion molecule-1 (VCAM-1) were detected by immunohistochemistry. The results showed that TCE-sensitized mouse kidneys were damaged and accompanied by increased serum ET-1. After treatment with CGS 35066, the inhibitor of endothelin converting enzyme-1 (ECE-1), kidney ET-1, TNF-α and VCAM-1 levels decreased, and renal function improved in TCE+CGS 35066-sensitized positive mice. In addition, kidney VEGF-A, glomerular endothelial cell glypican1 and syndecan1 levels increased, and endothelial cell damage was alleviated after treatment with CGS 35066. The results suggest that inhibiting ECE-1 could alleviate glomerular endothelial cell injury by inhibiting ET-1 expression, thus promoting endothelial cell repair by upregulating VEGF-A.

The role of microRNA-155 in glomerular endothelial cell injury induced by high glucose

ObjectiveTo investigate the role of microRNA-155-5p on apoptosis and inflammatory response in human renal glomerular endothelial cells (HRGEC) cultured with high glucose.MethodsThe primary HRGEC were mainly studied, light microscopy was used to detect changes in cell morphology. Quantitative Real Time-Polymerase Chain Reaction, Western Blot, immunofluorescence were aimed to observe the mRNA and protein expression levels of target gene ETS-1, downstream factors VCAM-1, MCP-1 and cleaved caspase-3 in each group after high glucose treatment as well as transfection with miR-155 mimics or inhibitor.ResultsThe expression of inflammatory factors and apoptosis of HRGEC cells increased under high glucose treatment. Compared with normal-glucose treatment, the expression of microRNA-155 markedly increased in HRGECs treated with high-glucose, as well as the mRNA and protein levels of ETS-1, VCAM-1, MCP-1 and cleaved caspase-3. Overexpression of microRNA-155 remarkably downregulated mRNA and protein levels of ETS-1, VCAM-1, MCP-1 and cleaved caspase-3, whereas miRNA-155 knockdown upregulated their levels. In addition, HRGEC cells were transfected with miR-155 mimics and ETS-1 siRNA with high glucose stimulation. The expression of ETS-1 was positively correlated with the expression of downstream factors VCAM-1 and MCP-1. These results suggest that ETS-1 can mediate endothelial cell inflammation by regulating VCAM-1 and MCP-1.ConclusionMiR-155 can negatively regulate the expression of target gene ETS-1 and its downstream factors VCAM-1, MCP-1 and cleaved caspase-3, thus mediating the inflammatory response and apoptosis of HRGEC.

Extracellular HMGB1 Induced Glomerular Endothelial Cell Injury via TLR4/MyD88 Signaling Pathway in Lupus Nephritis.

Previously, our study showed that HMGB1 was significantly elevated in the blood and located in the glomerular endothelium in LN patients. But whether extracellular HMGB1 is involved in the injury of glomerular endothelial cells (GECs) in LN still needs further investigation. Firstly, we detected the levels of SDC-1, VCAM-1, and proteinuria in LN patients and MRL/lpr mice and analyzed their correlations. Then, HMGB1 and TLR4/MyD88 were inhibited to observe the shedding of glycocalyx and injury of GECs in vivo and in vitro. Our results showed that HRGEC injury and SDC-1 shedding played an important role in the increase of permeability and proteinuria formation in LN. Additionally, inhibition of extracellular HMGB1 and/or downstream TLR4/MyD88/NF-κB/p65 signaling pathway also alleviated GEC monolayer permeability, reduced the shedding of the glomerular endothelial glycocalyx, improved the intercellular tight junction and cytoskeletal arrangement, and downregulated the NO level and VCAM-1 expression. These results suggested that extracellular HMGB1 might involve in GEC injury by activating the TLR4/MyD88 signaling pathway in LN, which provided novel insights and potential therapeutic target for the treatment of lupus nephritis.

Role of GRP56 in Glomerular Endothelial Cell Injury in Diabetic Kidney Disease

Role of GRP56 in Glomerular Endothelial Cell Injury in Diabetic Kidney Disease

Myeloperoxidase immunohistochemical staining can identify glomerular endothelial cell injury in dense deposit disease

Previous studies have demonstrated residual complement-mediated deposits in repeat kidney biopsies of C3 glomerulopathies (C3G) (dense deposit disease (DDD) and C3 glomerulonephritis) following eculizumab treatment, despite some clinical improvement. With residual complement deposition, it is difficult to determine whether there is a reduced complement-mediated endothelial cell injury. We validated that myeloperoxidase (MPO) immunohistochemical staining identified glomerular endothelial cell injury in crescentic glomerulonephritis and C3G. We report that MPO staining in the glomerular endothelium of the post-treatment kidney biopsy was significantly reduced after 3years of eculizumab treatment and clinical improvement in a 5-year-old boy with initial DDD and secondary crescent formation. We find that immunostaining for MPO is a useful method to compare glomerular endothelial injury in C3G following eculizumab treatment. This finding also supports the notion that eculizumab, a C5 blocker, may not mainly block C3 deposits in the glomeruli but significantly blocks final activation of the complement cascade, thus reducing glomerular endothelial cell injury.

METTL14 promotes glomerular endothelial cell injury and diabetic nephropathy via m6A modification of \u03b1-klotho

BackgroundN6-Methyladenosine (m6A) modification has been implicated in many bioprocesses. However, its functions in diabetic nephropathy (DN) have not been determined. Here, we investigated the role of METTL14, a key component of the m6A methyltransferase complex, in DN.MethodsThe expression of METTL14 was detected in DN patients and human renal glomerular endothelial cells (HRGECs). In vitro and in vivo experiments were performed to explore the functions of METTL14 on high glocse-induced HRGECs and renal injury of DN mice. We also investigated whether METTL14 works by regulating α-klotho expression through m6A modification.ResultsMETTL14 were highly expressed in kidneys of DN patients and high glocse-induced HRGECs both at the mRNA and protein level. Overexpression of METTL14 increased ROS, TNF-α and IL-6 levels and apoptosis in HRGECs. Conversely, METTL14 silence decreased the levels of ROS, TNF-α and IL-6 and cell apoptosis. We confirmed that METTL14 down-regulated α-klotho expression in an m6A-dependent manner. In addition, we also found that METTL14 aggravated renal injury and inflammation of db/db mice, which could partially rescued by α-klotho.ConclusionOur data revealed that METTL14 plays a vital role in high glucose-induced glomerular endothelial cells and diabetic nephropathy through m6A modification of α-klotho.

Telmisartan Mitigates High-Glucose-Induced Injury in Renal Glomerular Endothelial Cells (rGECs) and Albuminuria in Diabetes Mice.

Diabetic nephropathy (DN) is a common and severe complication of diabetes, impacting millions of people worldwide. High concentrations of serum glucose-associated injury of renal glomerular endothelial cells (rGECs) are involved in the DN pathogenesis. We found that exposure to high glucose increased the expression of angiotensin II type 1 receptor (AT1R) in human rGECs (hrGECs). To block the increased AT1R level, we used the newly developed antagonist Telmisartan. This study investigated whether Telmisartan possessed a beneficial effect against high-glucose-induced insults in hrGECs and explored the underlying mechanism. Our findings indicate that Telmisartan ameliorated high-glucose-induced mitochondrial dysfunction by increasing mitochondrial membrane potential. Also, Telmisartan attenuated oxidative stress by reducing the levels of two oxidative stress biomarkers 8-hydroxy-2 deoxyguanosine (8-OHDG) and malondialdehyde (MDA). Further, we found that Telmisartan prevented high-glucose-induced expression of NADPH oxidase 2 (NOX-2). Interestingly, exposure to high glucose resulted in the increased endothelial permeability of renal glomerular endothelial cells, which was mitigated by treatment with Telmisartan. Mechanistically, these effects are mediated by the MLCK/MLC-2/occludin signaling pathway. In the leptin-deficient db/db diabetic mouse model, we proved that Telmisartan treatment ameliorated the reduction of occludin and albuminuria. In conclusion, our findings demonstrate that Telmisartan possesses protective effects on high-glucose-induced injury to renal glomerular endothelial cells; its antagonizing of AT1R could be a potential therapeutic target in diabetic nephropathy.

Piperazine ferulate prevents high-glucose-induced filtration barrier injury of glomerular endothelial cells.

Filtration barrier injury induced by high glucose (HG) levels leads to the development of diabetic nephropathy. The endothelial glycocalyx plays a critical role in glomerular barrier function. In the present study, the effects of piperazine ferulate (PF) on HG-induced filtration barrier injury of glomerular endothelial cells (GEnCs) were investigated and the underlying mechanism was assessed. Immunofluorescence was used to observe the distribution of the glycocalyx as well as the expression levels of syndecan-1 and Zonula occludens-1 (ZO-1). Endothelial permeability assays were performed to assess the effects of PF on the integrity of the filtration barrier. Protein and mRNA expression levels were measured by western blotting and reverse transcription-quantitative PCR analyses, respectively. In vitro experiments revealed that adenosine monophosphate-activated protein kinase (AMPK) mediated HG-induced glycocalyx degradation and endothelial barrier injury. PF inhibited the HG-induced endothelial barrier injury and restored the expression levels of heparanase-1 (Hpa-1), ZO-1 and occludin-1 by AMPK. In vivo assays demonstrated that PF reduced the expression levels of Hpa-1, increased the expression levels of ZO-1 and attenuated glycocalyx degradation in the glomerulus. These data suggested that PF attenuated HG-induced filtration barrier injury of GEnC by regulating AMPK expression.

TRIM27 contributes to glomerular endothelial cell injury in lupus nephritis by mediating the FoxO1 signaling pathway

Tripartite motif-containing 27 (TRIM27) belongs to the triple motif (TRIM) protein family, which plays a role in a variety of biological activities. Our previous study showed that the TRIM27 protein was highly expressed in the glomerular endothelial cells of patients suffering from lupus nephritis (LN). However, whether TRIM27 is involved in the injury of glomerular endothelial cells in lupus nephritis remains to be clarified. Here, we detected the expression of the TRIM27 protein in glomerular endothelial cells in vivo and in vitro. In addition, the influence of TRIM27 knockdown on endothelial cell damage in MRL/lpr mice and cultured human renal glomerular endothelial cells (HRGECs) was explored. The results revealed that the expression of TRIM27 in endothelial cells was significantly enhanced in vivo and in vitro. Downregulating the expression of TRIM27 inhibited the breakdown of the glycocalyx and the injury of endothelial cells via the FoxO1 pathway. Moreover, HRGECs transfected with the WT-FoxO1 plasmid showed a reduction in impairment caused by LN plasma. Furthermore, suppression of the protein kinase B (Akt) pathway could attenuate damage by mediating the expression of TRIM27. Thus, the present study showed that TRIM27 participated in the injury of glomerular endothelial cells and served as a potential therapeutic target for the treatment of lupus nephritis.The expression of TRIM27 in MRL/lpr mice and human renal glomerular endothelial cells cultured in vitro is significantly enhanced. Downregulating the expression of TRIM27 inhibits the loss of glycocalyx and damage to endothelial cells through the FoxO1 pathway. In addition, inhibition of the protein kinase B (Akt) pathway can reduce the damage by mediating the expression of TRIM27.

Dasatinib Induced Reversible Nephrotic Range Proteinuria Occurs More Frequently Compared to Other Tyrosine Kinase Inhibitors in the Treatment of Chronic Myeloid Leukemia

Introduction: Dasatinib is an oral inhibitor of Abl and Src family of kinases. Dasatinib can cause a pleural effusion in 14% to 30% of patients as well as pulmonary arterial hypertension. Its mechanism is not fully elucidated although vascular endothelial growth factor (VEGF)-mediated mechanism has been proposed. In the literature, there are sporadic case reports of dasatinib-induced proteinuria/nephrotic syndrome. It is also suggested that dasatinib-induced kidney injury involves the interruption of VEGF signaling pathway.In the present study, we present a series of 6 patients, who developed nephrotic-range proteinuria while on dasatinib therapy that resolved after switch to other TKIs or discontinuation. Also, we have analyzed the risk of TKI-associated proteinuria according to the TKI subtype in 256 CML patients having available results of urine protein level.Patients and Methods: A total of 256 patients with CML on TKIs, with available urine testing were reviewed. TKI therapy was as follows: Imatinib (n=147), dasatinib (n=67), nilotinib (n=13), ponatinib (n=13) and bosutinib (n=16). First, we have reviwed spot urinalysis result for proteinuria screening, and further reviewed in detail the result of 24-hour urine protein measurement. If proteinuria is detected, we had in-depth chart review on the case to exclude other causes of proteinuria such as diabetes, renal failure, urinary tract infecion or urinary tract malignancies, etc. After excluding other causes of proteinuria, we have calculated the incidence rate of proteinuria using 1,000 person-year considering duration of exposure to TKI therapy.Results: With median duration of 35 months of dasatinib therapy, 6 patients (8.9%) developed nephrotic range proteinuria, after excluding other secondary causes of proteinuria. All received dasatinib as 2nd line following Imatinib front line therapy. Out of 6 patients with proteinuria, 4 patients developed pleural effusion prior to the development of proteinuria. All of them showed optimal molecular response to dasatinib therapy at the time of proteinuria development including MR4.5 (n=4), MR4.0 (n=1) or MMR (n=1).One patient underwent renal biopsy which showed chronic glomerular endothelial cell injury and thin basement membrane nephropathy, consistent with finding of minimal change disease. All 6 cases had discontinued (n=3) or switched to other TKI therapy (imatinib n=1; botutinib n=1; nilotinib n=1) with complete resolution of proteinuria. In the 3 patients who had MR4.5 or deeper response when dasatinib was discontinued due to proteinuria, one lost MMR after 3 months, one maintained MMR (+13 months), and another without losing undetectable transcript level (+21 months).The incidence rate of TKI-associated proteinuria was analyzed according to the TKI subtype in 256 CML patients. Median follow-up duration was 31 months for 35 months for dasatinib (1-105 months), imatinib (1-172 months), 27 months for nilotinib (1-63 months), 5 months for bosutinib (1-22 months), and 1 month for ponatinib (1-14 months), respectively. The exposure year was 201.8 years in dasatinib (n=67), 523.2 years in imatinib (n=147), 31.4 years in nilotinib (n=13), 6.1 years in bosutinib (n=16) and 1.4 years in ponatinib (n=13). The incidence rate of proteinuria in dasatinib treated group was calculated as 29/1,000 person-year, while it was 0 in imatinib, nilotinib, bosutinib, ponatinib-treated group, respectively due to no case confirmed to have proteinuria after excluding secondary causes of proteinuria (Fisher's exact test p<0.001).Conclusion: Development of nephrotic range proteinuria can be a toxicity from dasatinib therapy in CML treatment. Incidence rate is unexpectedly high at 29/1,000 person-year while there are no cases of nephrotic range proteinuria with exposure to other TKIs. All the proteinuria events were reversed completely after discontinuation/switch of dasatinib. Medical attention is to be paid for this unusual toxicity related to dasatinib therapy. Further study is strongly warranted to reach a clear conclusion for the incidence of this toxicity in a larger cohort. DisclosuresKim:BMS: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Paladin: Consultancy; Pfizer: Consultancy.