P1817DOES EPIGENETIC FACTORS LIKE HDAC2 PLAYS ROLE IN STEROID RESISTANCE VIA REGULATION OF P-GP AND MRP-1 IN CHILDHOOD IDIOPATHIC NEPHROTIC SYNDROME?

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
HARSHIT SINGH ◽  
Narayan Prasad ◽  
Vikas Agarwal ◽  
Akhilesh Kumar Jaiswal

Abstract Background and Aims The action of glucocorticoids is to switch off activated inflammatory genes. The activated glucocorticoid receptors (GR) interact with co-repressor molecules to impair NFκB-associated co-activator activity, reducing histone acetylation, chromatin remodelling. Reduction in histone acetylation occurs via recruitment of histone deacetylase (HDAC) 2 to the activated inflammatory gene complex by activated GR, resulting in efficacious suppression of activated inflammatory genes within the nucleus. To evaluate the effect HDAC 2 on P-gp and MRP-1 expression and function. Method Total of 78 subjects were considered in the study out of which 50 were steroid sensitive nephrotic syndrome (SSNS), and 28 were steroid resistant nephrotic syndrome (SRNS) patients. mRNA expression was analyzed on peripheral blood mononuclear cells (PBMCs) in SRNS patients (mean age 8.43±3.8 years), SSNS patients (mean age 7.54±3.5 years). PBMCs were treated with 1µM of Theophylline (HDAC2 stimulator) and 0.8µM of Trichostatin A (HDAC2 inhibitor) for a period of 48 hours. Quantitative PCR was performed using light cycler LC480 using SYBR green PCR technology with SYBR premix relative gene expression levels were calculated and normalized to the corresponding levels of the housekeeping gene (GAPDH). Results Expression of P-gp (4.79±0.970 v/s 2.13±0.72, p<0.0001) and MRP-1 (3.99 ±0.8 v/s 1.99 ±0.91, p<0.0001) on PBMCs was increased in SRNS as compared to that of SSNS. HDAC2 mRNA levels were significantly decreased in SRNS patients as compared to that of SSNS patients (2.97 ± 0.95 v/s 6.02 ± 1.13, p<0.0001). Theophylline(HDAC stimulator) for a period of 48 hours decreased mRNA levels of P-gp and MRP-1 in PBMCs of SRNS with maximal induction at 1µM (fold change 2.65 and 2.21, *p<0.0001) However HDAC2 mRNA expression increased significantly (fold change5.67, *p<0.0001). In SSNS patients P-gp and MRP-1 mRNA expression decreased at1µM (fold change 1.25, 1.24, *p<0.0001) while the mRNA expression was increased (fold change 6.93, *p<0.0001). TSA(HDAC inhibitor) for a period of 48 hours increased mRNA levels of P-gp and MRP-1 in PBMCs of SRNS with maximal induction at 0.8µM (fold change 7.51, 7.31, *p<0.0001) and significantly decreased the level of HDAC2 (fold change1.50, *p<0.0001) similarly in SSNS patients P-gp and MRP-1 mRNA expression increased at 0.8µM (fold change 3.49, 3.35, *p<0.0001) and HDAC2 decreased (fold change2.53, *p<0.0001) at 0.8µM. The functional activity of P-gp and MRP-1 was significantly higher in SRNS group as compared to SSNS group (p<0.001), whereas enzymatic activity of HDAC2 was increased in SSNS group as compared to SRNS group (p<0.001) Conclusion As we observed that HDAC2 regulates P-gp and MRP-1 efflux pumps, Inducer of HDAC2 may be a probable treatment stratergy for patients of Idiopathic Nephrotic Syndrome.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Birhan Alemnew ◽  
Soren T. Hoff ◽  
Tamrat Abebe ◽  
Markos Abebe ◽  
Abraham Aseffa ◽  
...  

Abstract Background Understanding immune mechanisms, particularly the role of innate immune markers during latent TB infection remains elusive. The main objective of this study was to evaluate mRNA gene expression patterns of toll-like receptors (TLRs) as correlates of immunity during latent TB infection and further infer their roles as potential diagnostic biomarkers. Methods Messenger RNA (mRNA) levels were analysed in a total of 64 samples collected from apparently healthy children and adolescents latently infected with tuberculosis (n = 32) or non-infected (n = 32). Relative expression in peripheral blood of selected genes encoding TLRs (TLR-1, TLR-2, TLR-4, TLR-6 and TLR-9) was determined with a quantitative real-time polymerase chain reaction (qRT-PCR) using specific primers and florescent labelled probes and a comparative threshold cycle method to define fold change. Data were analysed using Graph-Pad Prism 7.01 for Windows and a p-value less than 0.05 was considered statistically significant. Results An increased mean fold change in the relative expression of TLR-2 and TLR-6 mRNA was observed in LTBI groups relative to non-LTBI groups (p < 0.05), whereas a slight fold decrease was observed for TLR-1 gene. Conclusions An increased mRNA expression of TLR-2 and TLR-6 was observed in latently infected individuals relative to those non-infected, possibly indicating the roles these biomarkers play in sustenance of the steady state interaction between the dormant TB bacilli and host immunity.


2015 ◽  
Vol 19 (8) ◽  
pp. 454-456 ◽  
Author(s):  
Mohanapriya Chinambedu Dhandapani ◽  
Vettriselvi Venkatesan ◽  
Nammalwar Bollam Rengaswamy ◽  
Kalpana Gowrishankar ◽  
Prahlad Nageswaran ◽  
...  

Author(s):  
Aliou Abdoulaye Ndongo ◽  
Djibril Boiro ◽  
Idrissa Basse ◽  
Younoussa Kéita ◽  
Ndiogou Seck ◽  
...  

Background and Aim: Idiopathic nephrotic syndrome or nephrosis causes massive protein leakage in the urine. Its treatment requires steroids (prednisone, methylprednisolone), often for a prolonged period, notably in case of steroid-dependence or steroid-resistance. In children, long-term use of steroids can lead to several side effects such as statural growth retardation/ stunting. This study evaluated the frequency of stunting in idiopathic nephrotic syndrome in children on steroids and identified the associated factors.      Material and Methods: This was a retrospective, descriptive cohort study carried out in children aged 0 to 16 years treated at the paediatric nephrology unit of Aristide Le Dantec Hospital in Dakar, between 1 December 2017 and 31 May 2020. All records of nephrotic children treated in outpatient or inpatient setting were included. These children had to be on corticosteroid therapy for at least 30 months and have a height taken regularly during follow-up consultations. Results: Of 259 children followed for idiopathic nephrotic syndrome, 93 were included in the study. The median age was 96.5 months and the sex ratio was 1.9. The mean height of the children at the beginning of the follow-up was -0.26 DS, at the end it was -0.88 DS. At the beginning of the follow-up, 8 children had already stunting. At 12 months follow-up, 72 children (77.4%) had a decrease in z-score; and at 30 months, there were 7 more children (84.9%) who had a decrease in z-score. Methylprednisolone boluses were given to 17 children (18.3%). Calcium supplementation was done in 91 children (97.8%). Vitamin D supplementation was given to 91 children (97.8%). The mean number of relapses was 1.8. Factors associated with stunting were number of relapses ≤3 (p=0.03), duration of corticosteroid therapy >6 months (p<0.0001) and cumulative doses of prednisone >100 mg/kg (p=0.04). Conclusion: In prolonged nephrotic syndrome in children, corticosteroids can cause stunting.


2021 ◽  
Vol 9 ◽  
Author(s):  
Daojing Ying ◽  
Mengjie Jiang ◽  
Liping Rong ◽  
Hongjie Zhuang ◽  
Lizhi Chen ◽  
...  

Background: Studies have identified that MIF -173 G&gt;C gene polymorphism is associated with idiopathic nephrotic syndrome (INS) susceptibility and steroid resistance, but the results remain inconclusive.Methods: We searched PubMed, Embase, and Web of Science for relevant studies published before 31 March 2021. Pooled data were reported as odds ratio (OR) with 95% confidence interval (CI). Noteworthiness of significant OR was estimated by the false positive report probability (FPRP) test. Trial sequential analysis (TSA) was used to control type I and type II errors.Results: We selected seven case-control studies that included 1,026 INS children (362 were steroid-resistant NS and 564 were steroid-sensitive NS) and 870 controls. The results showed that MIF -173 G&gt;C polymorphism was significantly associated with INS susceptibility in allelic, heterozygous and dominant genetic models (C vs. G: OR = 1.325, 95% CI: 1.011-1.738; GC vs. GG: OR = 1.540, 95% CI: 1.249-1.899; CC + GC vs. GG: OR = 1.507, 95% CI: 1.231-1.845), and FPRP test and TSA indicated that the associations were true in heterozygous and dominant models. The pooled results also revealed that MIF -173 G&gt;C polymorphism was significantly associated with steroid resistance in allelic, homozygous and recessive models (C vs. G: OR = 1.707, 95% CI: 1.013-2.876; CC vs. GG: OR = 4.789, 95% CI: 2.109-10.877; CC vs. GC + GG: OR = 4.188, 95% CI: 1.831-9.578), but FPRP test indicated that all these associations were not noteworthy. Furthermore, TSA revealed that the non-significant associations between MIF -173 G&gt;C polymorphism and steroid resistance in heterozygous and dominant models were potential false negative.Conclusions: This meta-analysis could draw a firm conclusion that MIF -173 G&gt;C polymorphism was significantly associated with increased INS risk in heterozygous and dominant genetic models. MIF -173 G&gt;C polymorphism was not likely to affect steroid responsiveness, but more studies were needed to confirm.


2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Abolhassan Seyezadeh ◽  
Mohamad Reza Tohidi ◽  
Somaye Sheikhi ◽  
Mohammad Saleh Seyedzadeh ◽  
Sara Hookari

Background: Idiopathic Nephrotic Syndrome (INS), which is caused by a defect in the glomerular filtration barrier, is the most common chronic glomerular disease in children. Objectives: The present study aimed to assess the clinical features of INS and some recurrence-related factors in children. Methods: This population-based, cross-sectional study was conducted on 302 children with INS referring to the Pediatric Nephrology Clinic of Imam Reza Hospital of Kermanshah city, Iran, during 1998-2018. Results: The mean age (SD) at the time of diagnosis and the follow-up duration were 4.87 (2.89) years and 49.83 (37.52) months, respectively. The numbers of boys and girls were 185 (61.9%) and 114 (38.1%), respectively. The mean number (SD) of recurrences, annual recurrence rate during the follow-up, and the time to the first recurrence after responding to treatment were 1.71 (1.91), 0.48 (0.77), and 10.15 (10.63) months, respectively. The most common type of INS was steroid-dependent/frequent relapse, with a frequency of 151 (50.5%). Furthermore, 33 (11.0%) and 266 (89.0%) patients were resistant and respondent to treatment, respectively. There was a statistically significant relationship between age at the time of diagnosis and the type of INS (P = 0.007). Conclusions: This study revealed a statistically significant association between higher age and steroid resistance. However, in steroid responders, there was no relationship between gender, age at the time of diagnosis, and the time to the first recurrence, and the recurrence rate.


2017 ◽  
Vol 12 ◽  
pp. 117727191769583 ◽  
Author(s):  
Michael R Bennett ◽  
LaTawnya Pleasant ◽  
Christopher Haffner ◽  
Qing Ma ◽  
Wendy D Haffey ◽  
...  

Idiopathic nephrotic syndrome (NS) is the most common glomerular disorder of childhood. Response to initial treatment with corticosteroids is an indicator of prognosis, as resistant patients often present more progressive disease. In this cross-sectional pilot study, we set out to discover a panel of noninvasive biomarkers that could distinguish steroid-resistant nephrotic syndrome (SRNS) from steroid-sensitive nephrotic syndrome (SSNS). Information gleaned from such a panel could yield more individualized treatment plans and prevent unnecessary steroid exposure in patients unlikely to respond. Urine was collected from 50 pediatric patients diagnosed with idiopathic NS at Cincinnati Children’s Hospital Medical Center. Isobaric tags for relative and absolute quantitation (iTRAQ) was used to discover 13 proteins that were differentially expressed in SSNS vs SRNS in a small 5 × 5 discovery cohort. Suitable assays were found for 9 of the 13 markers identified by iTRAQ and were used in a 25 SRNS × 25 SSNS validation cohort. Vitamin D–binding protein (VDBP), alpha-1 acid glycoprotein 1 (AGP1), alpha-1 acid glycoprotein 2 (AGP2), alpha-1-B glycoprotein (A1BG), fetuin-A, prealbumin, thyroxine-binding globulin and hemopexin, and alpha-2 macroglobulin were measured and combined with urine neutrophil gelatinase–associated lipocalin (NGAL), which had been previously shown to distinguish patients with SRNS. Urinary VDBP, prealbumin, NGAL, fetuin-A, and AGP2 were found to be significantly elevated in SRNS using univariate analysis, with area under the receiver operating characteristic curves (AUCs) ranging from 0.65 to 0.81. Multivariate analysis revealed a panel of all 10 markers that yielded an AUC of 0.92 for identification of SRNS. A subset of 5 markers (including VDBP, NGAL, fetuin-A, prealbumin, and AGP2) showed significant associations with SRNS and yielded an AUC of 0.85.


2014 ◽  
Vol 92 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Ouafa Zerzaihi ◽  
Sabrina Chriett ◽  
Hubert Vidal ◽  
Luciano Pirola

Besides its direct metabolic effects, insulin induces transcriptional alterations in its target tissues. However, whether such changes are accompanied by epigenetic changes on the chromatin template encompassing insulin responsive genes is unclear. Here, mRNA levels of insulin-responsive genes hexokinase 2 (Hk2), insulin receptor substrate (Irs2), and the PI3K subunit p85β (Pik3r2) were compared in control versus insulin-stimulated L6 myotubes. Chromatin immunoprecipitation (ChIP) was performed with antibodies directed to histone H2A, histone variant H2A.Z, acetylated histone H3 on lysines 9/14, and acetylated H2A.Z. Insulin induced a more than 2-fold Hk2 mRNA increase, while Irs2 and Pik3r2 were downregulated. ChIP to H2A and H2A.Z showed higher H2A.Z accumulation around the transcriptional start site (TSS) of these insulin-modulated genes, while H2A.Z accumulation was lower distally to the TSS in the Hk2 promoter. H2A.Z levels and H3K9/14 acetylation correlated on several loci along the Hk2 gene, and H3K9/14 as well as H2A.Z acetylation was enhanced by insulin treatment. On the contrary, reduced H3K9/14 acetylation was observed in insulin-repressed Irs2 and Pik3r2, and recovery of acetylation by treatment with the histone deacetylase inhibitor trichostatin A reverted insulin-induced Irs2 downregulation. The chromatin regions encompassing selected insulin-responsive genes are thus featured by accumulation of H2A.Z around the TSS. H2A.Z accumulation facilitates insulin-dependent modulation of pharmacologically treatable H3K9/14 and H2A.Z acetylations. Indeed, inhibition of histone deacetylases by TSA treatment reverted insulin induced Irs2 gene downregulation. Dysregulated histone acetylation may thus be potentially targeted with histone deacetylase inhibitors.


Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Meint Volbeda ◽  
Daniela Jou-Valencia ◽  
Marius C. van den Heuvel ◽  
Marjolein Knoester ◽  
Peter J. Zwiers ◽  
...  

Abstract Background The mechanisms driving acute kidney injury (AKI) in critically ill COVID-19 patients are unclear. We collected kidney biopsies from COVID-19 AKI patients within 30 min after death in order to examine the histopathology and perform mRNA expression analysis of genes associated with renal injury. Methods This study involved histopathology and mRNA analyses of postmortem kidney biopsies collected from patients with COVID-19 (n = 6) and bacterial sepsis (n = 27). Normal control renal tissue was obtained from patients undergoing total nephrectomy (n = 12). The mean length of ICU admission-to-biopsy was 30 days for COVID-19 and 3–4 days for bacterial sepsis patients. Results We did not detect SARS-CoV-2 RNA in kidney biopsies from COVID-19-AKI patients yet lung tissue from the same patients was PCR positive. Extensive acute tubular necrosis (ATN) and peritubular thrombi were distinct histopathology features of COVID-19-AKI compared to bacterial sepsis-AKI. ACE2 mRNA levels in both COVID-19 (fold change 0.42, p = 0.0002) and bacterial sepsis patients (fold change 0.24, p < 0.0001) were low compared to control. The mRNA levels of injury markers NGAL and KIM-1 were unaltered compared to control tissue but increased in sepsis-AKI patients. Markers for inflammation and endothelial activation were unaltered in COVID-19 suggesting a lack of renal inflammation. Renal mRNA levels of endothelial integrity markers CD31, PV-1 and VE-Cadherin did not differ from control individuals yet were increased in bacterial sepsis patients (CD31 fold change 2.3, p = 0.0006, PV-1 fold change 1.5, p = 0.008). Angiopoietin-1 mRNA levels were downregulated in renal tissue from both COVID-19 (fold change 0.27, p < 0.0001) and bacterial sepsis patients (fold change 0.67, p < 0.0001) compared to controls. Moreover, low Tie2 mRNA expression (fold change 0.33, p = 0.037) and a disturbed VEGFR2/VEGFR3 ratio (fold change 0.09, p < 0.0001) suggest decreased microvascular flow in COVID-19. Conclusions In a small cohort of postmortem kidney biopsies from COVID-19 patients, we observed distinct histopathological and gene expression profiles between COVID-19-AKI and bacterial sepsis-AKI. COVID-19 was associated with more severe ATN and microvascular thrombosis coupled with decreased microvascular flow, yet minimal inflammation. Further studies are required to determine whether these observations are a result of true pathophysiological differences or related to the timing of biopsy after disease onset.


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