Genome-Wide Association Analysis of Protein-Coding Variants in IgA Nephropathy.

SIGNIFICANCE STATEMENT: Genome-wide association studies have identified nearly 20 IgA nephropathy susceptibility loci. However, most nonsynonymous coding variants, particularly ones that occur rarely or at a low frequency, have not been well investigated. The authors performed a chip-based association study of IgA nephropathy in 8529 patients with the disorder and 23,224 controls. They identified a rare variant in the gene encoding vascular endothelial growth factor A (VEGFA) that was significantly associated with a two-fold increased risk of IgA nephropathy, which was further confirmed by sequencing analysis. They also identified a novel common variant in PKD1L3 that was significantly associated with lower haptoglobin protein levels. This study, which was well-powered to detect low-frequency variants with moderate to large effect sizes, helps expand our understanding of the genetic basis of IgA nephropathy susceptibility. BACKGROUND: Genome-wide association studies have identified nearly 20 susceptibility loci for IgA nephropathy. However, most nonsynonymous coding variants, particularly those occurring rarely or at a low frequency, have not been well investigated. METHODS: We performed a three-stage exome chip-based association study of coding variants in 8529 patients with IgA nephropathy and 23,224 controls, all of Han Chinese ancestry. Sequencing analysis was conducted to investigate rare coding variants that were not covered by the exome chip. We used molecular dynamic simulation to characterize the effects of mutations of VEGFA on the protein's structure and function. We also explored the relationship between the identified variants and the risk of disease progression. RESULTS: We discovered a novel rare nonsynonymous risk variant in VEGFA (odds ratio, 1.97; 95% confidence interval [95% CI], 1.61 to 2.41; P = 3.61×10 -11 ). Further sequencing of VEGFA revealed twice as many carriers of other rare variants in 2148 cases compared with 2732 controls. We also identified a common nonsynonymous risk variant in PKD1L3 (odds ratio, 1.16; 95% CI, 1.11 to 1.21; P = 1.43×10 -11 ), which was associated with lower haptoglobin protein levels. The rare VEGFA mutation could cause a conformational change and increase the binding affinity of VEGFA to its receptors. Furthermore, this variant was associated with the increased risk of kidney disease progression in IgA nephropathy (hazard ratio, 2.99; 95% CI, 1.09 to 8.21; P = 0.03). CONCLUSIONS: Our study identified two novel risk variants for IgA nephropathy in VEGFA and PKD1L3 and helps expand our understanding of the genetic basis of IgA nephropathy susceptibility.

Effects of the portage early education program on Chinese children with global developmental delay.

Children with global developmental delay (GDD) were trained with the Portage Guide to Early Education (PGEE) program.In the treatment group, the PGEE program was performed on children with GDD (45 cases) through a combination of family and hospital interventions, in a 1-to-1 ratio. The Gesell Infant Development Scale (GESELL) developmental quotient (DQ) and social adaptability were measured before and 6 months after PGEE implementation in the treatment group. These parameters were also evaluated in a control group (30 cases) during an initial visit and 6 months later.Before the PGEE intervention, no significant differences were observed between the general characteristics of children in the control and treatment groups. Six months after the PGEE intervention, the DQ values of the children with GDD in the treatment group (64.7 ±â€Š9.5) were significantly higher than those before treatment (54.6 ±â€Š9.3) and those of the control group (58.3 ±â€Š10.2) (P < .05). The PGEE intervention significantly increased the DQ values on 5 aspects, including gross motor, fine motor, adaptability, language, and personal social activity abilities, and the scores on the Infants-Junior Middle School Students' Social-Life Abilities Scales (SM scales), as compared with the control group (P < .05).The PGEE program improves the DQ, social adaptability, and prognosis of children with GDD.

Circulating tumor DNA profiling reveals clonal evolution and real-time disease progression in advanced hepatocellular carcinoma.

Circulating tumor DNA (ctDNA) provides a potential non-invasive biomarker for cancer diagnosis and prognosis, but whether it could reflect tumor heterogeneity and monitor therapeutic responses in hepatocellular carcinoma (HCC) is unclear. Focusing on 574 cancer genes known to harbor actionable mutations, we identified the mutation repertoire of HCC tissues, and monitored the corresponding ctDNA features in blood samples to evaluate its clinical significance. Analysis of 3 HCC patients' mutation profiles revealed that ctDNA could overcome tumor heterogeneity and provide information of tumor burden and prognosis. Further analysis was conducted on the 4th HCC case with multiple lesion samples and sequential plasma samples. We identified 160 subclonal SNVs in tumor tissues as well as matched peritumor tissues with PBMC as control. 96.9% of this patient's tissue mutations could be also detected in plasma samples. These subclonal SNVs were grouped into 9 clusters according to their trends of cellular prevalence shift in tumor tissues. Two clusters constituted of tumor stem somatic mutations showed circulating levels relating with cancer progression. Analysis of tumor somatic mutations revealed that circulating level of such tumor stem somatic mutations could reflect tumor burden and even predict prognosis earlier than traditional strategies. Furthermore, HCK (p.V174M), identified as a recurrent/metastatic related mutation site, could promote migration and invasion of HCC cells. Taken together, study of mutation profiles in biopsy and plasma samples in HCC patients showed that ctDNA could overcome tumor heterogeneity and real-time track the therapeutic responses in the longitudinal monitoring.

Serum peptidome profiling for identifying pathological patterns in patients with primary nephrotic syndrome.

BACKGROUND: Renal biopsy is necessary for diagnosing the pathological changes of primary nephrotic syndrome (NS). However, it is invasive, time-consuming and can not be performed frequent on the same patient. Thus, development of a non-invasive and rapid diagnostic method may improve clinical patient management. METHODS: Proteomic tool magnetic bead-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MB-based MALDI TOF MS) was applied to serum to determine peptidome patterns that are characteristic of different pathological changes. RESULTS: Serum specimen from 114 patients with NS (62 were minimal change disease (MCD), 30 were membranous nephropathy (MN), and 22 were focal segmental glomerulosclerosis (FSGS)) and 60 normal individuals were analyzed using MB-based MALDI TOF MS. The peptidome pattern was generated by genetic algorithms using a training set of 31 MCD, 15 MN, 11 FSGS and 30 normal individuals and was validated by an independent testing set of the remaining samples. The serum peptidome pattern, based on a panel of 14 peaks, accurately recognized samples from MCD, MN, FSGS and healthy control with sensitivities of 93.5%, 86.7%, 63.6% and 90.0%, and specificities of 98.2%, 94.4%, 100% and 89.5%, respectively. Moreover, one peptide from peptidome pattern was identified by liquid chromatography tandem mass spectrometry (LC MS/MS) as fibrinogen A. CONCLUSION: Detection of the serum peptidome pattern is a rapid, non-invasive, high-throughout, and reproducible method for identifying the pathological patterns of patients with nephrotic syndrome.

Proteomic profiling identifies haptoglobin as a potential serum biomarker for steroid-resistant nephrotic syndrome.

BACKGROUND: Long-term outcomes for patients with adult idiopathic nephrotic syndrome correlate closely with steroid responsiveness. The aim of this prospective study was to evaluate the difference in serum proteomes between steroid-sensitive nephrotic syndrome (SSNS) and steroid-resistant nephrotic syndrome (SRNS) patients and identify potential biomarkers for the prediction of SRNS. METHODS: We performed a gel-based proteomic study of serum obtained from SRNS and SSNS patients and healthy controls at the time of presentation (n = 6 for each group). Proteins from the serum samples were separated using 2-D electrophoresis, digested in-gel and subjected to MALDI-TOF-MS/MS analysis. Further validation was performed utilizing Western blot and ELISA. The sensitivities and specificities of the candidate proteins for predicting SRNS were determined using receiver operating characteristic curves. RESULTS: Thirteen differentially expressed proteins were identified as haptoglobin (Hp) with different isoelectric points and molecular weights. Western blot and ELISA analysis of samples from 146 subjects (healthy controls = 52, SSNS = 54, SRNS = 40) showed a markedly increased level of Hp in the serum, but not urine, of SRNS compared to SSNS patients. The optimal serum cutoff level of Hp was set at ≥1,279 µg/ml using the receiver operating characteristic curve. The sensitivity and specificity for predicting SRNS were 85.0 and 96.3%, respectively. CONCLUSIONS: This study provides a novel overview of the difference in serum proteomes of SSNS and SRNS patients. Serum Hp may be a useful predictive biomarker for steroid therapy efficacy in the treatment of idiopathic nephrotic syndrome.

Glucose-based peritoneal dialysis fluids downregulate toll-like receptors and trigger hyporesponsiveness to pathogen-associated molecular patterns in human peritoneal mesothelial cells.

The objective of this study was to investigate the effects of glucose-based peritoneal dialysis (PD) fluids and icodextrin-based PD fluids on the expression of Toll-like receptor 2 (TLR2)/TLR4 and subsequent ligand-induced mitogen-activated protein kinase (MAPK) and NF-kappaB signaling and tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) mRNA expression in human peritoneal mesothelial cells (HPMCs). A human peritoneal mesothelial cell line (HMrSV5) was stimulated with glucose-based and icodextrin-based peritoneal dialysis fluids. Cell viability was assessed using MTT [3-(4,5-dimethylthiazolyl)-2,5-diphenyl-2H-tetrazolium bromide]. TLR2/TLR4 expression was determined by real-time PCR, Western blotting, and an immunofluorescence assay. In addition, cells were pretreated with different PD solutions and then incubated with Pam3CSK4 or lipopolysaccharide (LPS), and the degrees of MAPK and NF-kappaB activation were reflected by detecting the phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), p38, and p65, using a Western blot method. TNF-alpha and IL-1beta mRNA expression was measured by real-time PCR. Glucose-based peritoneal dialysis fluids suppressed the expression of TLR2 and TLR4 proteins in HPMCs. Challenge of cells with either Pam3CSK4 or LPS resulted in impaired TNF-alpha and IL-1beta production. Moreover, reduced TLR2 and TLR4 levels in glucose-based peritoneal dialysis solution-treated mesothelial cells were accompanied by reduced p42/44 (ERK1/2), JNK, p38 MAPK, and NF-kappaB p65 phosphorylation upon TLR ligand engagement. No significant changes in MAPK and NF-kappaB signaling and TNF-alpha and IL-1beta mRNA expression were observed in icodextrin-based PD solution-treated mesothelial cells. Glucose-based PD solution, but not icodextrin-based PD solution, downregulates expression of TLR2/TLR4 by human peritoneal mesothelial cells and triggers hyporesponsiveness to pathogen-associated molecular patterns.

[Cytokine in synovial monocytic cells from rheumatoid arthritis patients].

OBJECTIVE: To evaluate the inhibitory effect of blockade of Rho kinase upon mediating the secretion of proinflammatory cytokine in monocytic cells from rheumatoid arthritis (RA) patients. METHODS: Synovial fluid (SF) monocytic cells and peripheral blood monocytes (PB) from active RA patients were treated with TNFalpha or LPS respectively in the presence or absence of a specific ROK inhibitor, Y27632. ROK activity was assessed by Western blot and cytokine secretion measured by ELISA. RESULTS: Elevated ROK activity was found in synovial fluid monocytic cells from active RA patients. ROK activity was correlated with DAS, an index of disease activity of RA patients. ROK inhibitor Y27632 reduced the secretion of TNFalpha, IL-1beta and IL-6 in RA SF monocytic cells, but had no effect upon the secretion of IL-10, an anti-inflammatory cytokine. CONCLUSION: The present study provides novel evidence that ROK mediates the secretion of proinflammatory cytokines in monocytic cells from RA synovial fluids, suggesting a critical role of ROK in macrophage-mediated synovial inflammation of RA. Thus inhibition of ROK may be a new therapeutic target for RA.

Angiotensin II upregulates Toll-like receptor 4 and enhances lipopolysaccharide-induced CD40 expression in rat peritoneal mesothelial cells.

OBJECTIVE: Activation of Toll-like receptor 4 (TLR4) in peritoneal mesothelial cells by endotoxin contributes to peritoneal inflammation and fibrosis. Here we investigated TLR4 expression induced by angiotensin II (Ang II) and functional consequences of nuclear factor-kappaB (NF-kappaB) activation and CD40 expression in rat peritoneal mesothelial cells (RPMCs). METHODS: TLR4, CD40, tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) were determined by reverse transcription polymerase chain reaction (RT-PCR) and TLR4, IkappaBalpha, phospho-IkappaBalpha, NF-kappaB p65, and phospho-NF-kappaB p65 were analyzed by Western blot. The intracellular distribution of NF-kappaB p65 was detected by immunofluorescence. RESULTS: Treatment of RPMCs with Ang II resulted in an increase in the expression of TLR4 mRNA and protein levels. Preincubation of RPMCs with Ang II significantly increased lipopolysaccharide (LPS)-induced phospho-IkappaBalpha and phospho-NF-kappaB p65 protein (P < 0.05 vs. LPS alone) and CD40, TNF-alpha, and IL-6 mRNA levels (P < 0.05 vs. LPS alone). A significantly increased nuclear staining of NF-kappaB p65 in cells treated with Ang II plus LPS was also observed. CONCLUSIONS: Ang II upregulates the expression of TLR4 by RPMCs, resulting in enhanced NF-kappaB signaling and induction of CD40, TNF-alpha, and IL-6 expression. Locally produced Ang II in the peritoneum may have an amplified role in LPS-induced peritoneal inflammation.

Upregulation of rat renal cortical organic anion transporter (OAT1 and OAT3) expression in response to ischemia/reperfusion injury.

BACKGROUND/AIMS: Renal organic anion transporters (OAT1 and OAT3) localized in the basolateral membrane mediate the uptake of organic anions from the blood into proximal tubules. This study aimed to examine the effects of renal ischemia/reperfusion injury (IRI) on the expression of cortical renal OAT1 and OAT3 and the functional impact. METHODS: Male rats underwent a right nephrectomy and clamping of the left renal pedicle for 50 min or sham operation, followed by reperfusion for 1, 2, 4 and 6 days. The expression of OAT1 and OAT3 was detected by RT-PCR, immunohistochemistry and Western blot analysis. Na(+)-K(+)-ATPase activity was also estimated. RESULTS: The renal clearance of para-aminohippurate was significantly decreased on day 1 in IRI rats compared with sham-operated rats and returned to normal when the tubular injury recovered. There were significant increases in the mRNA and protein levels of OAT1 and OAT3 in renal cortex homogenates and basolateral membranes on day 1 after IRI, while on days 2 and 4 after IRI, the renal expression of OAT1 and OAT3 decreased gradually but was still significantly higher than that of the sham-operated rats. The Na(+)-K(+)-ATPase activity in renal cortex homogenates decreased significantly on day 1 after IRI but gradually increased on days 2, 4 and 6. CONCLUSIONS: Renal para-aminohippurate clearance was depressed in response to IRI; however, the expressions of renal cortex OAT1 and OAT3 were significantly elevated in the early stage of IRI which may have substantial impact on renal excretion of some drugs and toxic compounds.

Peroxisome proliferator-activated receptor-gamma is expressed by rat peritoneal mesothelial cells: its potential role in peritoneal cavity local defense.

BACKGROUND/AIMS: Peritoneal mesothelial cells (PMCs) play an important role in peritoneal inflammatory and immune response. It was reported that the peroxisomal proliferator-activated receptor-gamma (PPARgamma) ligand could effectively reduce inflammatory processes. However, the expression and function of PPARgamma in PMCs has not been reported. This study was to investigate the expression of PPARgamma in rat PMCs and the effect of PPARgamma activation on the production of CD40 and ICAM-1 induced by lipopolysaccharide (LPS). METHODS: Rat PMCs (RPMCs) were harvested from the peritoneal cavity of Sprague-Dawley rats and maintained under defined in vitro conditions. The cells were treated separately with LPS, 15d-PGJ(2), and ciglitazone at different time points. The mRNA and protein expression of PPARgamma, CD40 and ICAM-1 were detected by RT-PCR and Western blot, respectively. The intracellular distribution of PPARgamma was detected by immunocytochemistry. RESULTS: RPMCs expressed PPARgamma both at the mRNA and protein level. The specific signals for PPARgamma were mainly localized in the nucleus with weak staining in the cytoplasm. Stimulation of RPMCs with LPS resulted in a time-dependent increase in the expression of PPARgamma with the peak of mRNA at 3 h and protein at 12 h. Thereafter the expression of PPARgamma gradually attenuated. The mRNA expressions for CD40, ICAM-1 and protein expression of ICAM-1 were significantly upregulated following stimulation with LPS. Both 15d-PGJ(2) and ciglitazone decreased the expression of CD40 mRNA and ICAM-1 protein. However, ciglitazone was less effective than 15d-PGJ(2). CONCLUSIONS: There is constitutive expression of PPARgamma in cultured RPMCs and PPARgamma ligands which strongly inhibit LPS-induced CD40 and ICAM-1 production in RPMCs. It suggested that PPARgamma might play a part in the local defense of the peritoneal cavity by downregulating inflammatory mediators, which may play a potential role in preventing peritoneal fibrosis induced by peritonitis. Further in vivo study is needed to demonstrate the long-term effects.

Effect of 15d-PGJ2 on the expression of CD40 and RANTES induced by IFN-gamma and TNF-alpha on renal tubular epithelial cells (HK-2).

BACKGROUND/AIMS: Recent evidence shows that peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ameliorates a variety of inflammatory conditions. CD40 is a co-stimulatory molecule and its ligation induces production of different proinflammatory cytokines including RANTES (regulated upon activation, normal T cell expressed), which are considered as important factors in the initiation and maintenance of inflammatory response. The aim of this study was to investigate the effect of PPAR-gamma on CD40 and RANTES production on cultured human renal proximal tubular epithelial (HK-2) cells. METHODS: HK-2 cells were maintained under defined in vitro conditions and treated with either PPAR-gamma agonist 15-deoxy-12,14-prostaglandin J2 (15d-PGJ2) or 15d-PGJ2 + PPAR-gamma antagonist GW9662, and then stimulated with a combination of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). The CD40 and RANTES levels were investigated. RESULTS: HK-2 cells expressed low levels of CD40 and RANTES. Activation of HK-2 cells by combined treatment of TNF-alpha and IFN-gamma results in strong synergistic effects on the expression of CD40 and the secretion of RANTES. 15d-PGJ2 significantly decreased CD40 and RANTES expression and GW9662 partly abrogated the inhibition of 15d-PGJ2 on CD40 and RANTES. CONCLUSION: 15d-PGJ2 significantly decreased CD40 and RANTES expression in HK-2 cells, which were partially mediated by PPAR-gamma-dependent pathways. These results point to PPAR-gamma as a remarkable new target in the prevention of tubular inflammatory injury associated with renal disease.

[Angiotensin II up-regulates osteopontin mRNA expression of RAW264.7 macrophages via p38MAPK signaling].

OBJECTIVE: To investigate the changes of osteopontin (OPN) mRNA expression induced by angiotensin II (AngII) in RAW264.7 macrophages, and to determine the role of p38 mitogen-activated protein kinase (p38MAPK) signaling in up-regulation of OPN mRNA expression. METHODS: RT-PCR was used for examining the OPN mRNA expression, and the phosphorylation of p38MAPK and activating transcription factor2 (ATF2) was detected by Western blot. RESULTS: (1) AngII (1 micromol/L) enhanced the expression of OPN mRNA in RAW264.7 macrophages with time-dependent, including 0.9 fold, 2.3 folds and 2.4 folds up-regulation at 6, 12, 24 h, respectively (all P < 0.01), whereas there was no significant change in negative control at 0 h and 24 h, suggesting that the mRNA expression of OPN is inducible. (2) Following excitation by Ang II in vitro, there was substantial up-regulation of OPN mRNA expression in RAW264.7 macrophages with dose-dependent; with a dose of 1 micromol/L incubated for 12 h, Ang II increased the OPN mRNA expression by 2.6 folds (P < 0.01). (3) Pre-treatment with SB202190 (5 micromol/L) for 30 min in RAW264.7 macrophages before AngII (1 micromol/L) used, the expression of OPN mRNA was inhibited by 61.7% (P < 0.01); but no marked inhibition had happened at the time of treatment with both SB202190 (5 micromol/L) and Ang II (1 micromol/L) added at the same time and with SB202190 (5 micromol/L) for 120 min after Ang II (1 micromol/L) used. (4) Pre-treatment with SB202190 (1, 5, 10 micromol/L) for 30 min in RAW264.7 macrophages before Ang II (1 micromol/L) used, the expression of OPN mRNA was decreased by 43.4%, 63.0% and 65.5%, respectively (all P < 0.01). (5) There was a maximal expression of p38MAPK phosphorylation at 15 approximately 30 min induced by Ang II (1 micromol/L) in RAW264.7 macrophages, and the maximal expression of phosphorylated ATF2 was at 30 approximately 45 min. (6) Pre-treatment with SB202190 (1, 5 micromol/L) for 30 min in RAW264.7 macrophages before Ang II (1 micromol/L) used, the expression of p38MAPK phosphorylation was inhibited markedly with dose-dependent, and the phosphorylation of p38MAPK was decreased by 61.7% (P < 0.01) after the SB202190 (5 micromol/L) was used. CONCLUSION: Angiotensin II may up-regulate osteopontin mRNA expression of RAW264.7 macrophages via p38MAPK signaling.