TGFβ1 is a powerful regulator of fibrosis; secreted in a latent form, it becomes active after release from the latent complex. During tissue fibrosis, the EDA + isoform of cellular fibronectin is overexpressed. In pulmonary fibrosis it has been proposed that the fibronectin splice variant including an EDA domain (FN EDA+) activates latent TGFβ. Our work investigates the potential of blocking the 'splicing in' of EDA with antisense oligonucleotides to inhibit TGFβ1-induced EDA + fibronectin and to prevent the cascade of events initiated by TGFβ1 in human renal proximal tubule cells (PTEC). Human primary PTEC were treated with TGFβ1 for 48 h, medium removed and the cells transfected with RNase H-independent antisense oligonucleotides (ASO) designed to block EDA exon inclusion (ASO5). The efficacy of ASO to block EDA exon inclusion was assessed by EDA + fibronectin RNA and protein expression; the expression of TGFβ, αSMA (α smooth muscle actin), MMP2 (matrix metalloproteinse-2), MMP9 (matrix metalloproteinse-9), Collagen I, K Cadherin and connexin 43 was analysed. Targeting antisense oligonucleotides designed to block EDA exon inclusion in fibronectin pre mRNA were effective in reducing the amount of TGFβ1 -induced cellular EDA + fibronectin RNA and secreted EDA + fibronectin protein (assessed by western immunoblotting and immunocytochemistry) in human proximal tubule cells in an in vitro cell culture model. The effect was selective for EDA + exon with no effect on EDB + fibronectin RNA and total fibronectin mRNA. Exogenous TGFβ1 induced endogenous TGFβ, αSMA, MMP2, MMP9 and Col I mRNA. TGFβ1 treatment for 48h reduced the expression of K-Cadherin and increased the expression of connexin-43. These TGFβ1-induced pro-fibrotic changes were attenuated by ASO5 treatment. 48 h after the removal of exogenous TGFβ, further increases in αSMA, MMP2, MMP9 was observed; ASO5 significantly inhibited this subsequent increase. ASO5 treatment also significantly inhibited ability of the cell culture medium harvested at the end of the experiment (96h) to stimulate SMAD3 reporter cells. The role of endogenous TGFβ1 was confirmed by the use of a TGFβ receptor inhibitor. Our results demonstrate a critical role of FN EDA+ in a cycle of TGFβ driven pro-fibrotic responses in human PTEC and blocking its production with ASO technology offers a potential therapy to interrupt this vicious circle and hence limit the progression of renal fibrosis.

It is predicted that electronic waste (e-waste) derived principally from discarded electronic equipment will reach 74 million metric tonnes by 2030. In addition, urbanization and industrialization have contributed to metal contamination in the environments. E-waste is often deposed of in low-income countries adversely affecting the health of the working population. The main sources of e-contamination are soil, dust, and food matrices. Drinking water can also be contaminated with heavy metals such as arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) causing a major health concern. Exposure to pollutants present in waste has a significant detrimental impact on human health; children in developing countries are often particularly susceptible. Sensitive monitoring procedures are needed to improve the rate of detection and monitoring of the possible adverse effects on the population exposed to significant quantities of e-waste.

The gradual spread of Aspergilli worldwide is adding to the global shortage of food and is affecting its safe consumption. Aspergillus-derived mycotoxins, including aflatoxins and ochratoxin A, and fumonisins (members of the fusariotoxin group) can cause pathological damage to vital organs, including the kidney or liver. Although the kidney functions as the major excretory system in mammals, monitoring and screening for mycotoxin induced nephrotoxicity is only now a developmental area in the field of livestock feed toxicology. Currently the assessment of individual exposure to mycotoxins in man and animals is usually based on the analysis of toxin and/or metabolite contamination in the blood or urine. However, this requires selective and sensitive analytical methods (e.g., HPLC-MS/MS), which are time consuming and expensive. The toxicokinetic of mycotoxin metabolites is becoming better understood. Several kidney biomarkers are used successfully in drug development, however cost-efficient, and reliable kidney biomarkers are urgently needed for monitoring farm animals for early signs of kidney disease. β2-microglobulin (β2-MG) and N-acetyl-β-D-glucosaminidase (NAG) are the dominant biomarkers employed routinely in environmental toxicology research, while kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) are also emerging as effective markers to identify mycotoxin induced nephropathy. Pigs are exposed to mycotoxins due to their cereal-based diet and are particularly susceptible to Aspergillus mycotoxins. In addition to commonly used diagnostic markers for nephrotoxicity including plasma creatinine, NAG, KIM-1 and NGAL can be used in pigs. In this review, the currently available techniques are summarized, which are used for screening mycotoxin induced nephrotoxicity in farm animals. Possible approaches are considered, which could be used to detect mycotoxin induced nephropathy.

Abstract Background The 1-year cumulative incidence of AKI reportedly is high (52%) in pediatric neoplastic disorders. About half of these events occur within 2 weeks. However, subclinical AKI episodes may remain unrecognized by the conventional creatinine-based approaches. We investigated the diagnostic value of urinary N-acetyl-β-D-glucosaminidase (uNAG) as an early marker of acute kidney injury (AKI). Methods In our retrospective study, 33 children with neoplastic disorders were inculded who had serial uNAG tests (at least 5 samples/patient) with a total of 367 uNAG measurements. Renal function was determined by cystatin-C and creatinine based GFR, and relative increase of uNAG index (uNAGRI). We focused on detecting both clinical and subclinical AKI episodes (according to Biomarker-Guided Risk Assessment using pRIFLE criteria and /or elevated uNAG levels) and the incidence of chronic kidney damage. Results Sixty episodes in 26 patients, with positivity at least in one parameter of kidney panel, were identified during the observation period. We detected 18/60 clinical and 12/60 subclinical renal episodes. In 27/60 episodes only uNAG values was elevated with no therapeutic consequence at presentation. Two patients were detected with decreased initial creatinine levels with 3 „silent” AKI. In 13 patients, modest elevation of uNAG persisted suggesting mild, reversible tubular damage, while chronic tubuloglomerular injury occurred in 5 patients. Based on ROC analysis for the occurence of AKI, uNAGRI significantly indicated the presence of AKI, the sensitivity and specificity are higher than the changes of GFRCreat. Serial uNAG measurements are recommended for the reduction of the great amount of false positive uNAG results, often due to overhydratation. Conclusion Use of Biomarker-guided Risk Assessment for AKI identified 1.5 × more clinical and subclinical AKI episodes than with creatinine alone in our pediatric cancer patients. Based on the ROC curve for the occurence of AKI, uNAGRI has relatively high sensitivity and specificity comparable to changes of GFRCysC. The advantage of serial uNAG measurements is to decrease the number of false positive results. Trial registration The consent to participate is not applicable because it was not reqired for ethical approval and it is a retrospectiv study.

Environmental and occupational exposure to heavy metals and metalloids is a major global health risk. The kidney is often a site of early damage. Nephrotoxicity is both a major consequence of heavy metal exposure and potentially an early warning of greater damage. A paradigm shift occurred at the beginning of the 21st century in the field of renal medicine. The medical model of kidney failure and treatment began to give way to a social model of risk factors and prevention with important implications for environmental health. This development threw into focus the need for better biomarkers: markers of exposure to known nephrotoxins; markers of early damage for diagnosis and prevention; markers of disease development for intervention and choice of therapy. Constituents of electronic waste, e-waste or e-pollution, such as cadmium (Cd), lead (Pb), mercury (HG), arsenic (As) and silica (SiO2) are all potential nephrotoxins; they target the renal proximal tubules through distinct pathways. Different nephrotoxic biomarkers offer the possibility of identifying exposure to individual pollutants. In this review, a selection of prominent urinary markers of tubule damage is considered as potential tools for identifying environmental exposure to some key metallic pollutants.

SummaryRenal risk stratification in systemic immunoglobulin light‐chain (AL) amyloidosis is according to estimated glomerular filtration rate (eGFR) and urinary protein creatinine ratio (uPCR), the latter attributed to glomerular dysfunction, with proximal tubular dysfunction (PTD) little studied. Urinary retinol binding protein 4 (uRBP), a low molecular weight tubular protein and highly sensitive marker of PTD, was prospectively measured in 285 newly diagnosed, untreated patients with systemic AL amyloidosis between August 2017 to August 2018. At diagnosis, the uRBP/creatinine ratio (uRBPCR) correlated with serum creatinine (r = 0·618, P < 0·0001), uPCR (r = 0·422, P < 0·0001) as well as both fractional excretion of phosphate and urate (r = 0·563, P < 0·0001). Log uRBPCR at diagnosis was a strong independent predictor of end‐stage renal disease {hazard ratio [HR] 2·65, [95% confidence interval (CI) 1·06–6·64]; P = 0·038}, particularly in patients with an eGFR >30 ml/min/1.73 m2 [HR 4·11, (95% CI 1·45–11·65); P = 0·008] and those who failed to achieve a deep haematological response to chemotherapy within 3 months of diagnosis [HR 6·72, (95% CI 1·83–24·74); P = 0·004], and also predicted renal progression [HR 1·91, (95% CI 1·18–3·07); P = 0·008]. Elevated uRBPCR indicates PTD and predicts renal outcomes independently of eGFR, uPCR and clonal response in systemic AL amyloidosis. The role of uRBPCR as a novel prognostic biomarker merits further study, particularly in monoclonal gammopathies of renal significance.

Background Retinol-binding protein4 (RBP) assays using polyclonal antibodies (pRBP) have major problems of non-linearity of dilution and a very small useable dynamic range. Our objective was to develop a specific assay with a wider dynamic range to detect tubular proteinuria. Methods mRBP (monoclonal capture and second antibody with colorimetric detection) and fluoroimmunoassays for RBP (fRBP) (polyclonal capture and monoclonal second antibody with fluorescence detection) were developed and compared with pRBP. Four hundred and eighty-eight patient samples were collected; 290 samples were analysed by mRBP and 198 samples with fRBP and compared with pRBP. Results mRBP assay has the advantages of better linearity on dilution and wider analytical range over pRBP. It is limited by poor signal in the patients with albuminuria and glomerular proteinuria and inferior discrimination between patient groups. fRBP had an intra-assay and inter-assay CV of <6% and <8%, respectively, and analytical range was 2.3–599 µg/L. fRBP was linear on dilution within the analytical range. Correlation (r) was 0.8722 (95% CI 0.7621 to 0.9333, P< 0.0001); Mann-Whitney test revealed no significant difference (U = 18,877, n = 198, P = 0.5244) asserting that the medians of the two samples were identical. Bland-Altman test between pRBP and fRBP showed a mean negative bias of 16.43 (CI –994 to 1027) µg/mmol. Conclusions The combination assay with fluorescence detection (fRBP) proved more discriminatory than a purely monoclonal system especially in patients with significant proteinuria and has advantages of better linearity on dilution and wider analytical range than the existing pRBP assay and compared extremely well with pRBP.

The intensifying world-wide spread of mycotoxigenic fungal species has increased the possibility of mycotoxin contamination in animal feed and the human food chain. Growing evidence shows the deleterious toxicological effects of mycotoxins from infants to adults, while large population-based screening programs are often missing to identify affected individuals. The kidney functions as the major excretory system, which makes it particularly vulnerable to nephrotoxic injury. However, few studies have attempted to screen for kidney injury biomarkers in large, mycotoxin-exposed populations. As a result, there is an urgent need to screen them with sensitive biomarkers for potential nephrotoxicity. Although a plethora of biomarkers have been tested to estimate the harmful effects of a wide spectrum of toxicants, β2-microglobulin (β2-MG) and N-acetyl-β-D-glucosaminidase (NAG) are currently the dominant biomarkers employed routinely in environmental toxicology research. Nevertheless, kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) are also emerging as useful and informative markers to reveal mycotoxin induced nephrotoxicity. In this opinion article we consider the nephrotoxic effects of mycotoxins, the biomarkers available to detect and quantify the kidney injuries caused by them, and to recommend biomarkers to screen mycotoxin-exposed populations for renal damage.

AbstractBackground: In the kidney glucose is freely filtered by the glomerulus and, mainly, reabsorbed by sodium glucose cotransporter 2 (SGLT2) expressed in the early proximal tubule. Human proximal tubule epithelial cells (PTECs) undergo pathological and fibrotic changes seen in diabetic kidney disease (DKD) in response to elevated glucose. We developed a specific in vitro model of DKD using primary human PTECs with exposure to high D-glucose and TGF-β1 and propose a role for SGLT2 inhibition in regulating fibrosis. Methods: Western blotting was performed to detect cellular and secreted proteins as well as phosphorylated intracellular signalling proteins. qPCR was used to detect CCN2 RNA. Gamma glutamyl transferase (GT) activity staining was performed to confirm PTEC phenotype. SGLT2 and ERK inhibition on high D-glucose, 25 mM, and TGF-β1, 0.75 ng/ml, treated cells was explored using dapagliflozin and U0126, respectively. Results: Only the combination of high D-glucose and TGF-β1 treatment significantly up-regulated CCN2 RNA and protein expression. This increase was significantly ameliorated by dapagliflozin. High D-glucose treatment raised phospho ERK which was also inhibited by dapagliflozin. TGF-β1 increased cellular phospho SSXS Smad3 serine 423 and 425, with and without high D-glucose. Glucose alone had no effect. Smad3 serine 204 phosphorylation was significantly raised by a combination of high D-glucose+TGF-β1; this rise was significantly reduced by both SGLT2 and MEK inhibition. Conclusions: We show that high D-glucose and TGF-β1 are both required for CCN2 expression. This treatment also caused Smad3 linker region phosphorylation. Both outcomes were inhibited by dapagliflozin. We have identified a novel SGLT2 -ERK mediated promotion of TGF-β1/Smad3 signalling inducing a pro-fibrotic growth factor secretion. Our data evince support for substantial renoprotective benefits of SGLT2 inhibition in the diabetic kidney.

The consensus of The European Renal Cancer Roundtable meeting held in Brussels in 2019 was that the most pressing challenge is improved early detection. Each year sees around 400 000 new cases of kidney cancer worldwide. The 10 countries with the highest rates of kidney cancer are all in Europe; from Belarus to Iceland. Renal Cell Carcinoma (RCC) accounts for 80% of all kidney cancers. RCC are reported as a diverse group such as clear cell (-70% of the total) and of proximal tubule origin as well as papillary (~10%) and chromophobe (~5%), the latter 2 of distal tubule origin with a large number of gene mutations [1]. Yet, there are few causal genes driving RCC. The VHL gene is a common initiating mutation in Clear Cell RCC (ccRCC) but loss of VHL function is insufficient to develop ccRCC. There are environmental/behavioural associations with RCC including some of the usual suspects, smoking and obesity as well regular or prolonged acetaminophen use. When pre-metastatic RCC is treated, usually with surgery, 5and 10-year survival rates are good. 5-year survival rates for metastatic RCC are generally poor, less than 10%, despite the use of antiangiogenic tyrosine kinase inhibitors such as sunitinib. Unfortunately, due to substantial renal reserve more than 50% of RCC are detected incidentally and often when it has already spread [2].

Abstract Background and Aims Cardiovascular morbidity and mortality are increased in kidney transplant patients. High blood pressure (BP) contributes significantly to this risk and is associated with shortened allograft survival. Dietary salt reduction is widely recommended as a strategy to lower BP in the general population and in chronic kidney disease. Due to a lack of evidence there is currently no consensus on dietary salt restriction in kidney transplant patients. The primary aim of the study was to examine the impact of reduced dietary salt intake on BP in kidney transplant patients. Method Sixty stable kidney transplant patients, ≥ 6-months post-transplantation, with BP ≥120/80 mmHg, and sodium intake ≥80 mmol/24hrs, were randomised in this parallel-designed study to receive either a regular-salt diet (target 150 mmol/24hr) or a low-salt diet (target 80 mmol/24hr) for 8-weeks. The primary outcome measure was systolic and diastolic BP. Secondary outcome measures included 24-hour ambulatory BP (ABP) and proteinuria. Dietary salt intake was assessed by 48-hour urinary sodium excretion. Results At baseline, patients (72% men) were 56±11 years with estimated glomerular filtration rate (eGFR) 53±18 mL/min/1.73m2. Mean urinary sodium was 128±42 mmol/24hr, mean systolic BP was 132±12 mmHg, and mean diastolic BP was 77±10 mmHg. At the end of the intervention period sodium excretion was significantly lower in the low-salt group compared with the regular-salt group (90±37 vs. 132±51 mmol/24hr; adjusted mean difference, -36 [95% CI, -59 to -14] mmol/24hr; P=0.002). We found no difference in systolic BP (adjusted mean difference, -2 [95% CI, -12 to 9] mmHg; P=0.750), diastolic BP (adjusted mean difference, 0 [95% CI, -4 to 4] mmHg; P=0.887), 24-hour systolic ABP (adjusted mean difference, -3 [95% CI, -9 to 2] mmHg; P=0.213) or 24-hour diastolic ABP (adjusted mean difference, -2 [95% CI, -5 to 1] mmHg; P=0.267). There was no significant effect on proteinuria or eGFR. Conclusion In this study baseline urinary sodium was lower than expected and baseline BP was well controlled. Reducing dietary salt by 2g/day did not have a significant effect on office blood pressure readings.

Airway epithelial tight junction (TJ) proteins form a resistive barrier to the external environment, however, during respiratory bacterial infection TJs become disrupted compromising barrier function. This promotes glucose flux/accumulation into the lumen which acts as a nutrient source for bacterial growth. Metformin used for the treatment of diabetes increases transepithelial resistance (TEER) and partially prevents the effect of bacteria but the mechanisms of action are unclear. We investigated the effect of metformin and Staphylococcus aureus on TJ proteins, zonula occludins (ZO)-1 and occludin in human airway epithelial cells (H441). We also explored the role of AMP-activated protein kinase (AMPK) and PKC zeta in metformin-induced effects. Pretreatment with metformin prevented the S. aureus-induced changes in ZO-1 and occludin. Metformin also promoted increased abundance of full length over smaller cleaved occludin proteins. The nonspecific PKC inhibitor staurosporine reduced TEER but did not prevent the effect of metformin indicating that the pathway may involve atypical PKC isoforms. Investigation of TJ reassembly after calcium depletion showed that metformin increased TEER more rapidly and promoted the abundance and localization of occludin at the TJ. These effects were inhibited by the AMPK inhibitor, compound C and the PKC zeta pseudosubstrate inhibitor (PSI). Metformin increased phosphorylation of occludin and acetyl-coA-carboxylase but only the former was prevented by PSI. This study demonstrates that metformin improves TJ barrier function by promoting the abundance and assembly of full length occludin at the TJ and that this process involves phosphorylation of the protein via an AMPK-PKC zeta pathway.

The interactions of the extracellular matrix (ECM) proteins with cells strongly regulate cell behaviour. The glomerular basement membrane (GBM) is a dynamic structure made up of protein secreted by endothelial cells and podocyte. These proteins could regulate the behaviour of these cells in health and diseases. Extra Domain A + Fn (EDA+Fn) is an alternatively spliced form of Fibronectin (Fn) recently identified in GBM and a recognised marker of various pathologies. In this study for the first time, we have investigated the responses of human podocytes cultured on different composition of GBM proteins which are cellular Fn (EDA+), plasma Fn (EDA-) and collagen IV. Conditionally immortalised human podocyte were grown on the dishes coated with different matrices; collagen IV (Col IV), cellular fibronectin (CFn) containing the EDA Exon, plasma fibronectin (PFn), which lacks the EDA Exon (EDA-Fn). We have performed western blotting to characterise the expression of the different proteins, real time PCR and RT-PCR to look for gene expression and alternative splicing of EDA+Fn. We have used TGFβ1 as a stimulator. We have used HEK-Blue-hTLR4 cells to determine the biological activity of cellular Fn. Conditionally immortalised human podocyte show marked differences in their morphology grown on the dishes coated with different matrices; Col IV, CFn, and PFn. CFn was biologically active as it activated the TLR4 signalling in HEK-Blue-hTLR4 cells. Different matrices effects basal as well as TGFβ1 mediated alternative splicing of EDA+Fn. TGFβ1 was active on different matrices as it induced phosphorylation of pSmad3 however it did not affect phosphorylation of pAkt and p38. Interestingly, different cellular matrices affected basal phosphorylation of pAkt. CFn downregulated gene expression of synaptopodin and increased gene expression of collagen I and Fn. CFn increased cell death in detached human podocytes. Alteration of the constituents of the GBM is likely to significantly alter podocyte cellular responses to growth factors involved in podocytopathies, such as TGFβ.

Alternative splicing is an important gene regulation process to distribute proteins in health and diseases. Extra Domain A+ Fibronectin (EDA+Fn) is an alternatively spliced form of fibronectin (Fn) protein, present in the extra cellular matrix (ECM) and a recognised marker of various pathologies. TGFβ1 has been shown to induce alternative splicing of EDA+Fn in many cell types. Podocytes are spectacular cell type and play a key role in filtration and synthesise ECM proteins in renal physiology and pathology. In our previous study we have demonstrated expression and alternative splicing of EDA+Fn in basal condition in human podocytes culture. TGFβ1 further induced the basal expression and alternative splicing of EDA+Fn through Alk5 receptor and SR proteins. In this study, we have investigated TGFβ1 mediated signalling involved in alternative splicing of EDA+Fn in human podocytes. We have performed western blotting to characterise the expression of the EDA+Fn protein and other signalling proteins and RT-PCR to look for signalling pathways involved in regulation of alternative splicing of EDA+Fn in conditionally immortalised human podocytes culture.We have used TGFβ1 as a stimulator and SB431542, SB202190 and LY294002 for inhibitory studies. In this work, we have demonstrated in human podocytes culture TGFβ1 2.5ng/ml induced phosphorylation of Smad1/5/8, Smad2 and Smad3 via the ALK5 receptor. TGFβ1 significantly induced the PI3K/Akt pathway and the PI3K/Akt pathway inhibitor LY294002 significantly downregulated basal as well as TGFβ1 induced alternative splicing of EDA+Fn in human podocytes. In addition to this, TGFβ1 significantly induced the p38 MAP kinase signalling pathway and p38 MAP kinase signalling pathway inhibitor SB202190 downregulated the TGFβ1-mediated alternative splicing of EDA+Fn in human podocytes. The results with PI3K and p38 MAP kinase signalling pathway suggest that inhibiting PI3K signalling pathway downregulated the basal alternative splicing of EDA+Fn in human podocytes and its the inhibition of p38 Map Kinase signalling pathway which had specifically downregulated the TGFβ1 mediated alternative splicing of EDA+Fn in human podocytes culture. Activation of TGFβ1-mediated Smad1/5/8 via Alk5 receptor suggests that TGFβ1 signalling pathway involved Alk5/Alk1 receptor axis signalling in human podocytes.

Growth factors like TGFβ and CTGF (CCN2) plays a vital role in various cellular functions. TGFβ and CTGF are overexpressed in renal fibrosis. CTGF act as profibrotic stimuli to TGFβ. CCN3 is a member of CCN family which also comprises CCN1 (CYR61), CCN2 (CTGF), CCN4 (WISP-1), CCN5 (WISP-2) and CCN6 (WISP-3). CCN3 has been shown to antagonise CTGF. In this study, we investigated the role of CCN3 in TGFβ1-mediated signalling in human podocytes culture. This study describes the novel function of CCN3 in regulation of TGFβ1 mediated non-canonical Smad signalling in human podocytes culture. Experiments were conducted on conditionally immortalised human podocytes incubated with TGFβ1 (1.25ng/ml and 2.5ng/ml) and CCN3 (360ng/ml). Western blot study was performed to study signalling proteins. RT-PCR was performed to study alternative splicing of Fibronectin (Fn). Real time PCR was performed to look for gene expression of Fn and collagen IV and collagen I. TGFβ1 induced the Smad1/5/8, Smad3 and p38 phosphorylation and CCN3 downregulated the TGFβ1 induced Smad1/5/8 phosphorylation and did not affect Smad3 and p38 phosphorylation. In addition to this CCN3 induced alternative splicing of Extra domain A Fibronectin (EDA+Fn). CCN3 also induced collagen IV, Collagen I and Fn gene expression. This is the first evidence of downregulation of TGFβ-mediated activation of a Smad1/5/8 signalling pathway by CCN3 in human podocytes and in any cell type. Targeting CCN3-mediated events could provide exciting outcomes in the understanding of molecular mechanism of fibrosis.

Alternative splicing is a fundamental phenomenon to build protein diversity in health and diseases. Extra Domain A+ Fibronectin (EDA+Fn) is an alternatively spliced form of fibronectin protein present in the extra cellular matrix (ECM) in renal fibrosis. Podocytes are spectacular cell type and play a key role in filtration and synthesise ECM proteins in renal physiology and pathology. TGFβ1 is a strong stimulator of ECM proteins in renal injury. In this study, we have investigated alternative splicing of EDA+ Fn in human podocytes in response to TGFβ1. We have performed western blotting and immunofluorescence to characterise the expression of the EDA+Fn protein, real-time PCR for RNA expression and RT-PCR to look for alternative splicing of EDA+Fn in conditionally immortalised human podocytes culture.We used TGFβ1 as a stimulator and SB431542 and SRPIN340 for inhibitory studies. In this work, for the first time we have demonstrated in human podocytes culture EDA+Fn is expressed in the basal condition and TGFβ1 2.5ng/ml induced the Fn mRNA and EDA+Fn protein expression demonstrated by real-time PCR, western blotting and immunofluorescence. TGFβ1 2.5ng/ml induced the alternative splicing of EDA+Fn shown by conventional RT-PCR. Studies with ALK5 inhibitor SB431542 and SRPIN340 show that TGFβ1 induced alternative splicing of EDA+Fn was by the ALK5 receptor and the SR proteins.  In human podocytes culture, alternative splicing of EDA+Fn occurs at basal conditions and TGFβ1 further induced the alternative splicing of EDA+Fn via ALK5 receptor activation and SR proteins. This is the first evidence of basal and TGFβ1 mediated alternative splicing of EDA+Fn in human podocytes culture.

Cytochrome P450 2D6 (CYP2D6) is a clinically important CYP, metabolising approximately 25% common drugs. We investigated the clinical effect of acute kidney injury (AKI) on hepatic CYP2D6 metabolism in critically ill adults, using the probe drug tramadol (abstract 470). We found no effect of AKI but a strong CYP2D6 genotype/phenotype influence on tramadol metabolism. Rodent studies indicate no change or impaired CYP2D6 metabolism in chronic kidney disease and AKI (Refs [1–3]). No published human or animal data has examined CYP2D6 transcription, translation or activity in AKI. Previously we demonstrated no change in CYP2D6 transcription when pooled serum from patients with end-stage kidney disease (ESKD) was applied to human HepG2 cells, known to express the functional CYP2D6*1 allele.