CFAP47 is a novel causative gene implicated in X-linked polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a well-described condition in which ~80% of cases have a genetic explanation, while the genetic basis of sporadic cystic kidney disease in adults remains unclear in ~30% of cases. This study aimed to identify novel genes associated with polycystic kidney disease (PKD) in patients with sporadic cystic kidney disease in which a clear genetic change was not identified in established genes. A next-generation sequencing panel analyzed known genes related to renal cysts in 118 sporadic cases, followed by whole-genome sequencing on 47 unrelated individuals without identified candidate variants. Three male patients were found to have rare missense variants in the X-linked gene Cilia And Flagella Associated Protein 47 (CFAP47). CFAP47 was expressed in primary cilia of human renal tubules, and knockout mice exhibited vacuolation of tubular cells and tubular dilation, providing evidence that CFAP47 is a causative gene involved in cyst formation. This discovery of CFAP47 as a newly identified gene associated with PKD, displaying X-linked inheritance, emphasizes the need for further cases to understand the role of CFAP47 in PKD.

Genetic Diagnosis of Adult Hemodialysis Patients With Unknown Etiology

Introduction

Kidney disease of unknown etiology accounts for 1 in 10 adult end-stage renal disease (ESRD) cases worldwide. The aim of this study is to clarify the genetic background of patients with chronic kidney disease (CKD) of unknown etiology who initiated renal replacement therapy (RRT) in adulthood.

Methods

This is a multicenter cross-sectional cohort study. Of the 1164 patients who attended 4 dialysis clinics in Japan, we first selected patients who started RRT between the ages of 20 and 49 years. After excluding patients with apparent causes of CKD (e.g., diabetic nephropathy, polycystic kidney disease (PKD) with family history, patients who underwent renal biopsy), 90 patients with CKD of unknown cause were included. The 298 genes associated with CKD were analyzed using capture-based targeted next-generation sequencing.

Results

Of the 90 patients, 10 (11.1%) had pathogenic variants in CKD-causing genes and 17 (18.9%) had variant of unknown significance (VUS). Three patients had PKD1 pathogenic variants, and 1 patient had PKD1 and COL4A4 pathogenic variants. In addition, 2 patients were diagnosed with atypical hemolytic uremic syndrome (aHUS) due to C3 or CFHR5. One patient each was diagnosed with Alport syndrome due to COL4A4 and COL4A3 variants, nephronophthisis due to NPHP1 variants, Fabry disease due to GLA variants, and autosomal-dominant tubulointerstitial kidney disease due to UMOD variants. Genetic diagnoses were not concordant with clinical diagnoses, except for patients with PKD1 variant.

Conclusion

This largest study on genetic analysis in hemodialysis-dependent adults revealed the presence of undiagnosed inherited kidney diseases.

Signaling mechanisms in renal compensatory hypertrophy revealed by multi-omics

Loss of a kidney results in compensatory growth of the remaining kidney, a phenomenon of considerable clinical importance. However, the mechanisms involved are largely unknown. Here, we use a multi-omic approach in a unilateral nephrectomy model in male mice to identify signaling processes associated with renal compensatory hypertrophy, demonstrating that the lipid-activated transcription factor peroxisome proliferator-activated receptor alpha (PPARα) is an important determinant of proximal tubule cell size and is a likely mediator of compensatory proximal tubule hypertrophy.

Circadian gene expression in mouse renal proximal tubule

Circadian variability in kidney function is well recognized but is often ignored as a potential confounding variable in physiological experiments. Here, we have created a data resource consisting of expression levels for mRNA transcripts in microdissected proximal tubule segments from mice as a function of the time of day. Small-sample RNA sequencing was applied to microdissected S1 proximal convoluted tubules and S2 proximal straight tubules. After stringent filtering, the data were analyzed using JTK-Cycle to detect periodicity. The data set is provided as a user-friendly webpage at https://esbl.nhlbi.nih.gov/Databases/Circadian-Prox2/. In proximal convoluted tubules, 234 transcripts varied in a circadian manner (4.0% of the total). In proximal straight tubules, 334 transcripts varied in a circadian manner (5.3%). Transcripts previously known to be associated with corticosteroid action and with increased flow were found to be overrepresented among circadian transcripts peaking during the "dark" portion of the day [zeitgeber time (ZT)14-22], corresponding to peak levels of corticosterone and glomerular filtration rate in mice. To ask whether there is a time-of-day dependence of protein abundances in the kidney, we carried out LC-MS/MS-based proteomics in whole mouse kidneys at ZT12 and ZT0. The full data set (n = 6,546 proteins) is available at https://esbl.nhlbi.nih.gov/Databases/Circadian-Proteome/. Overall, 293 proteins were differentially expressed between ZT12 and ZT0 (197 proteins greater at ZT12 and 96 proteins greater at ZT0). Among the regulated proteins, only nine proteins were found to be periodic in the RNA-sequencing analysis, suggesting a high level of posttranscriptional regulation of protein abundances.NEW & NOTEWORTHY Circadian variation in gene expression can be an important determinant in the regulation of kidney function. The authors used RNA-sequencing transcriptomics and LC-MS/MS-based proteomics to identify gene products expressed in a periodic manner. The data were used to construct user-friendly web resources.

Absence of ULK1 decreases AMPK activity in the kidney, leading to chronic kidney disease progression

AMP-activated protein kinase (AMPK) inactivation in chronic kidney disease (CKD) leads to energy status deterioration in the kidney, constituting the vicious cycle of CKD exacerbation. Unc-51-like kinase 1 (ULK1) is considered a downstream molecule of AMPK; however, it was recently reported that the activity of AMPK could be regulated by ULK1 conversely. We demonstrated that AMPK and ULK1 activities were decreased in the kidneys of CKD mice. However, whether and how ULK1 is involved in the underlying mechanism of CKD exacerbation remains unknown. In this study, we investigated the ULK1 involvement in CKD, using ULK1 knockout mice. The CKD model of Ulk1^-/- mice exhibited significantly exacerbated renal function and worsening renal fibrosis. In the kidneys of the CKD model of Ulk1^-/- mice, reduced AMPK and its downstream β-oxidation could be observed, leading to an energy deficit of increased AMP/ATP ratio. In addition, AMPK signaling in the kidney was reduced in control Ulk1^-/- mice with normal renal function compared to control wild-type mice, suggesting that ULK1 deficiency suppressed AMPK activity in the kidney. This study is the first to present ULK1 as a novel therapeutic target for CKD treatment, which regulates AMPK activity in the kidney.

Data resource: vasopressin-regulated protein phosphorylation sites in the collecting duct

Vasopressin controls renal water excretion through actions to regulate aquaporin-2 (AQP2) trafficking, transcription, and degradation. These actions are in part dependent on vasopressin-induced phosphorylation changes in collecting duct cells. Although most efforts have focused on the phosphorylation of AQP2 itself, phosphoproteomic studies have identified many vasopressin-regulated phosphorylation sites in proteins other than AQP2. The goal of this bioinformatics-based review is to create a compendium of vasopressin-regulated phosphorylation sites with a focus on those that are seen in both native rat inner medullary collecting ducts and cultured collecting duct cells from the mouse (mpkCCD), arguing that these sites are the best candidates for roles in AQP2 regulation. This analysis identified 51 vasopressin-regulated phosphorylation sites in 45 proteins. We provide resource web pages at https://esbl.nhlbi.nih.gov/Databases/AVP-Phos/ and https://esbl.nhlbi.nih.gov/AVP-Network/, listing the phosphorylation sites and describing annotated functions of each of the vasopressin-targeted phosphoproteins. Among these sites are 23 consensus protein kinase A (PKA) sites that are increased in response to vasopressin, consistent with a central role for PKA in vasopressin signaling. The remaining sites are predicted to be phosphorylated by other kinases, most notably ERK1/2, which accounts for decreased phosphorylation at sites with a X-p(S/T)-P-X motif. Additional protein kinases that undergo vasopressin-induced changes in phosphorylation are Camkk2, Cdk18, Erbb3, Mink1, and Src, which also may be activated directly or indirectly by PKA. The regulated phosphoproteins are mapped to processes that hypothetically can account for vasopressin-mediated control of AQP2 trafficking, cytoskeletal alterations, and Aqp2 gene expression, providing grist for future studies.NEW & NOTEWORTHY Vasopressin regulates renal water excretion through control of the aquaporin-2 water channel in collecting duct cells. Studies of vasopressin-induced protein phosphorylation have focused mainly on the phosphorylation of aquaporin-2. This study describes 44 phosphoproteins other than aquaporin-2 that undergo vasopressin-mediated phosphorylation changes and summarizes potential physiological roles of each.

Safety and feasibility of autologous cord blood infusion for improving motor function in young children with cerebral palsy in Japan: A single-center study

INTRODUCTION

Cerebral palsy (CP) is the most prevalent motor disorder of childhood. It typically results from in utero or perinatal brain injury. Recently, it has been reported that autologous cord blood (ACB) infusion for children with CP improved gross motor function and brain connectivity, but unfortunately, it has never been tried in Japan. We conducted a pilot study of the infusing of ACB, which was delivered from private bank, in the children with CP to assess the safety and feasibility to the procedure as well as any effect in improving neurological function.

METHODS

After demonstrating the induction of tissue regeneration in animal model studies conducted a single-arm pilot study of intravenous ACB infusion in 6 young Japanese children with CP (ages 1-6 years). Primary outcomes were safety assessed by vital signs, clinical symptoms, and blood and urinary examinations at baseline and 1 weeks, 1, 2 and 3 years after treatment. In addition, motor function evaluations, neurodevelopmental examinations, magnetic resonance imaging, and electroencephalography (EEG) were performed at the same time.

RESULTS

Infusion was generally well-tolerated, although one patient experienced microhematuria 1 year after treatment and another one patient experienced febrile convulsion once 9 months after treatment. These events were transient, no relapse was seen during observation study. All patients improved a median of 6.8 points on the 1-year Gross Motor Functional Measure-66 (GMFM-66) scores, greater than predicted by age and severity. Furthermore, the 2-year and 3-year GMFM-66 scores were also greater than expected (median 6.2 points and 5.5 points, respectively). Overall scales and language-social scales of the developmental quotient (DQ) improved in 3 of 6 patients, who had greater changes in their GMFM-66 scores than the other cases after treatment. There were no significant correlations among the GMFM-66 scores, DQ, and infusion cell counts.

CONCLUSION

ACB infusion was safe and feasible for clinical use in patients with CP. However, much more clinical study with larger numbers of patients and in-depth studies of treatment mechanism of CP are needed.

Prevalence and implications of exercise pulmonary hypertension in chronic thromboembolic pulmonary disease

Introduction

Recent international statement on chronic thromboembolic pulmonary hypertension proposed the definition of chronic thromboembolic pulmonary disease (CTEPD) and advocated further research regarding its clinical characteristic, natural history, and therapeutic strategy. Exercise pulmonary hypertension (Ex-PH) has been considered a mild degree of pulmonary hypertension (PH) among patients with normal pulmonary hemodynamics at rest. However, the clinical significance of Ex-PH in CTEPD remains unknown.

Purpose

In the patients with CTEPD, we aimed to verify 1) the prevalence and clinical profiles of Ex-PH, 2) effect of BPA on pulmonary vascular response after exercise in Ex-PH, 3) long-term clinical outcomes of conservative management in non-Ex-PH.

Methods

We retrospectively reviewed 26 patients with CTEPD (median age 65 years, 38% male), who underwent cardiopulmonary exercise test with right heart catheterization (CPET-RHC). The definitions of CTEPD are the following 1) pulmonary artery occlusion due to organic thrombus confirmed by imaging studies after ≥3 months of anticoagulation, 2) mPAP<25 mmHg and PAWP≤15 mmHg at rest. PQslope was plotted using multipoint plots. Ex-PH was defined by PQ slope>3.0, and the patients were divided into Ex-PH and non-Ex PH groups. Clinical profiles and long-term outcomes were compared between two groups. The patients in Ex-PH groupunderwent CPET-RHC 6–12 months after balloon pulmonary angioplasty (BPA). In Non-Ex-PH group, serial measurements of echocardiography were performed.

Results

Overall, 5 and 21 patients were categorized as CTEPD with PH (mPAP 21–24mmHg) and without PH (mPAP≤20mmHg), and 14 and 12 were categorized Ex-PH and non-Ex-PH groups, respectively. Although all 5 patients with CTEPD with PH were classified as Ex-PH group (Figure 1), there was no significant difference in baseline hemodynamics at rest between Ex-PH and non-Ex-PH groups (mPAP: 19.5 [18.4–20.6] vs. 17.7 [16.6–18.9] mmHg, PVR: 2.2 [1.7–2.7] vs. 2.3 [1.9–2.8] wood units, P>0.05, respectively). PQ slope was significantly higher in Ex-PH group (4.6 [3.2–6.0] vs. 1.31 [0.2–2.8], p=0.002). There were no differences in respiratory function test, blood gas analysis, and 6-minute walk distance between two groups. There were no major adverse events such as all-cause mortality and hospitalization for PH in overall cohort. Among Ex-PH group, BPA decreased PQslope (4.8 [3.6–6.4] to 2.3 [1.9–3.0], p<0.05). Among no-Ex-PH group, there was no significant change in tricuspid regurgitation pressure gradient (28 [17–33] to 27 [21–36] mmHg, p>0.05) over the 997 [651–1451] days.

Conclusion

Ex-PH was common in patients with CTEPD, and there were no clinical profiles differentiating Ex-PH from non-Ex-PH, except parameters of CPET-RHC. BPA improved an abnormal pulmonary vascular response to exercise in Ex-PH. The conservative management in non-Ex-PH was feasible. Randomized clinical trials will be needed to further investigate this treatment strategy.

Funding Acknowledgement

Type of funding sources: None.

Different changes in the biomarker C-terminal telopeptides of type II collagen (CTX-II) following intra-articular injection of high molecular weight hyaluronic acid and oral non-steroidal anti-inflammatory drugs in patients with knee osteoarthritis: a multi-center randomized controlled study

OBJECTIVES

We previously reported, based on a multicenter randomized-control study, that the efficacy of intra-articular injections of hyaluronic acid (IA-HA) was not inferior to that of oral non-steroidal anti-inflammatory drugs (NSAIDs) in patients with knee osteoarthritis (OA). However, the molecular effects on the pathophysiology of knee OA remain unclear. C-terminal telopeptides of type II collagen (CTX-II) is reported to primarily originate from the interface between articular cartilage and subchondral bone, which is a site of potential remodeling in OA. We performed a predefined sub-analysis of the previous study to compare the changes of urinary CTX-II (uCTX-II) in response to IA-HA to those in response to NSAID for knee OA.

DESIGN

A total of 200 knee OA patients were registered from 20 hospitals and randomized to receive IA-HA (2,700 kDa HA, 5 times at 1-week intervals) or NSAID (loxoprofen sodium, 180 mg/day) for 5 weeks. The uCTX-II levels were measured before and after treatment.

RESULTS

The uCTX-II levels were significantly increased by IA-HA treatment (337.7 ± 193.8 to 370.7 ± 234.8 ng/μmol Cr) and were significantly reduced by NSAID treatment (423.2 ± 257.6 to 370.3 ± 250.9 ng/μmol Cr). The %changes of uCTX-II induced by IA-HA (11.6 ± 29.5%) and NSAID (-9.0 ± 26.7%) was significantly different (between-group difference: 20.6, 95% confidence intervals: 10.6 to 30.6).

CONCLUSIONS

While both IA-HA and NSAID improved symptoms of knee OA, uCTX-II levels were increased by IA-HA and reduced by NSAIDs treatment, suggesting these treatments may improve symptoms of knee OA through different modes of action.

Systems Biology of the Vasopressin V2 Receptor: New Tools for Discovery of Molecular Actions of a GPCR

Systems biology can be defined as the study of a biological process in which all of the relevant components are investigated together in parallel to discover the mechanism. Although the approach is not new, it has come to the forefront as a result of genome sequencing projects completed in the first few years of the current century. It has elements of large-scale data acquisition (chiefly next-generation sequencing-based methods and protein mass spectrometry) and large-scale data analysis (big data integration and Bayesian modeling). Here we discuss these methodologies and show how they can be applied to understand the downstream effects of GPCR signaling, specifically looking at how the neurohypophyseal peptide hormone vasopressin, working through the V2 receptor and PKA activation, regulates the water channel aquaporin-2. The emerging picture provides a detailedframework for understanding the molecular mechanisms involved in water balance disorders, pointing the way to improved treatment of both polyuric disorders and water-retention disorders causing dilutional hyponatremia.

"ADPKD-omics": determinants of cyclic AMP levels in renal epithelial cells

The regulation of cyclic adenosine monophosphate (cAMP) levels in kidney epithelial cells is important in at least 2 groups of disorders, namely water balance disorders and autosomal dominant polycystic kidney disease. Focusing on the latter, we review genes that code for proteins that are determinants of cAMP levels in cells. We identify which of these determinants are expressed in the 14 kidney tubule segments using recently published RNA-sequencing and protein mass spectrometry data ("autosomal dominant polycystic kidney disease-omics"). This includes G protein-coupled receptors, adenylyl cyclases, cyclic nucleotide phosphodiesterases, cAMP transporters, cAMP-binding proteins, regulator of G protein-signaling proteins, G protein-coupled receptor kinases, arrestins, calcium transporters, and calcium-binding proteins. In addition, compartmentalized cAMP signaling in the primary cilium is discussed, and a specialized database of the proteome of the primary cilium of cultured "IMCD3" cells is provided as an online resource (https://esbl.nhlbi.nih.gov/Databases/CiliumProteome/). Overall, this article provides a general resource in the form of a curated list of proteins likely to play roles in determination of cAMP levels in kidney epithelial cells and, therefore, likely to be determinants of progression of autosomal dominant polycystic kidney disease.

Aerotaxis and aerokinesis of Dictyostelium discoideum under hypoxic microenvironments

Although spatiotemporal changes of oxygen in a microenvironment are known to affect the cellular dynamics of various eukaryotes, the details are not fully understood. Here, we describe the aerotaxis and aerokinesis of Dictyostelium discoideum (Dd), which has long been employed as a model organism for eukaryotic cells. We developed a microfluidic device capable of time-lapse observation of cultured cells while controlling oxygen concentrations in microchannels. Migratory behaviors of Dd were observed and quantitatively evaluated under an oxygen concentration gradient from 0% to 21% O₂, as well as in various uniform oxygen conditions. In a hypoxic region within the oxygen concentration gradient, Dd migrated toward regions of higher oxygen concentration at increased velocity, which was independent of cell density. Observed under uniform oxygen concentrations of 1%, 2%, 3%, and 21%, the migration velocity of Dd increased significantly in hypoxic environments of 2% O₂ or less. Thus, Dd shows aerotaxis, directed by the oxygen concentration gradient, and simultaneously shows aerokinesis, changing the migration velocity according to the oxygen concentration itself.

Reduced default mode network connectivity relative to white matter integrity is associated with poor cognitive outcomes in patients with idiopathic normal pressure hydrocephalus

BACKGROUND

The aim of this study was to investigate whether default mode network (DMN) connectivity and brain white matter integrity at baseline were associated with severe cognitive impairments at baseline and poor cognitive outcomes after shunt placement in patients with idiopathic normal pressure hydrocephalus (iNPH).

METHODS

Twenty consecutive patients with iNPH whose symptoms were followed for 6 months after shunt placement and 10 healthy controls (HCs) were enrolled. DMN connectivity and brain white matter integrity at baseline in the patients with iNPH and HCs were detected by using resting-state functional magnetic resonance imaging (MRI) with independent component analysis and diffusion tensor imaging, respectively, and these MRI indexes were compared between the patients with iNPH and HCs. Performance on neuropsychological tests for memory and executive function and on the gait test was assessed in the patients with iNPH at baseline and 6 months after shunt placement. We divided the patients with iNPH into the relatively preserved and reduced DMN connectivity groups using the MRI indexes for DMN connectivity and brain white matter integrity, and the clinical measures were compared between the relatively preserved and reduced DMN connectivity groups.

RESULTS

Mean DMN connectivity in the iNPH group was significantly lower than that in the HC group and was significantly positively correlated with Rey auditory verbal learning test (RAVLT) immediate recall scores and frontal assessment battery (FAB) scores. Mean fractional anisotropy of the whole-brain white matter skeleton in the iNPH group was significantly lower than that in the HC group. The reduced DMN connectivity group showed significantly worse performance on the RAVLT at baseline and significantly worse improvement in the RAVLT immediate recall and recognition scores and the FAB scores than the preserved DMN connectivity group. Moreover, the RAVLT recognition score highly discriminated patients with relatively preserved DMN connectivity from those with relatively reduced DMN connectivity.

CONCLUSIONS

Our findings indicated that iNPH patients with reduced DMN connectivity relative to the severity of brain white matter disruption have severe memory deficits at baseline and poorer cognitive outcomes after shunt placement. However, further larger-scale studies are needed to confirm these findings.

Bispectral Index™ variation during living donor liver transplantation in a child with hepatic encephalopathy: a case report

Background

It is unclear whether perioperative Bispectral Index™ (BIS) monitoring in pediatric cases with acute liver failure (ALF) is effective for evaluation of neurological function. We describe a pediatric patient with hepatic encephalopathy (HE) in whom the BIS value increased from low levels to the normal range during liver transplantation (LT).

Case presentation

Electroencephalography in a 6-year-old comatose girl diagnosed with ALF and HE who was unresponsive to pain and auditory stimuli revealed continuous slow waves, and hence, emergency LT was performed. Intraoperatively, BIS values remained low until reperfusion. However, BIS value variability increased after reperfusion. She was subsequently discharged without any neurological sequelae.

Conclusions

Low BIS values were considered to reflect the severity of HE. It is possible that improvement of the BIS value and waveform was a reflection of graft function. BIS monitoring might be a good indicator of neurological recovery after LT.

Bayesian identification of candidate transcription factors for the regulation of Aqp2 gene expression

Aquaporin-2 (Aqp2) gene transcription is strongly regulated by vasopressin in the renal collecting duct. However, the transcription factors (TFs) responsible for the regulation of expression of Aqp2 remain largely unknown. We used Bayes' theorem to integrate several -omics data sets to stratify the 1,344 TFs present in the mouse genome with regard to probabilities of regulating Aqp2 gene transcription. Also, we carried out new RNA sequencing experiments mapping the time course of vasopressin-induced changes in the transcriptome of mpkCCD cells to identify TFs that change in tandem with Aqp2. The analysis identified 17 of 1,344 TFs that are most likely to be involved in the regulation of Aqp2 gene transcription. These TFs included eight that have been proposed in prior studies to play a role in Aqp2 regulation, viz., Cebpb, Elf1, Elf3, Ets1, Jun, Junb, Nfkb1, and Sp1. The remaining nine represent new candidates for future studies (Atf1, Irf3, Klf5, Klf6, Mef2d, Nfyb, Nr2f6, Stat3, and Nr4a1). Conspicuously absent is CREB (Creb1), which has been widely proposed to mediate vasopressin-induced regulation of Aqp2 gene transcription (Nielsen S, Frokiaer J, Marples D, Kwon TH, Agre P, Knepper MA. Physiol Rev 82: 205-244, 2002; Kortenoeven ML, Fenton RA. Biochim Biophys Acta 1840: 1533-1549, 2014; Bockenhauer D, Bichet DG. Nat Rev Nephrol 11: 576-588, 2015; Pearce D, Soundararajan R, Trimpert C, Kashlan OB, Deen PM, Kohan DE. Clin J Am Soc Nephrol 10: 135-146, 2015). Instead, another CREB-like TF, Atf1, ranked fourth among all TFs. RNA sequencing time-course experiments showed a rapid increase in Aqp2 mRNA, within 3 h of vasopressin exposure. This response was matched by an equally rapid increase in the abundance of the mRNA coding for Cebpb, which we have shown by chromatin immunoprecipitation-sequencing studies to bind downstream from the Aqp2 gene. The identified TFs provide a roadmap for future studies to understand regulation of Aqp2 gene expression.NEW & NOTEWORTHY Abetted by the advent of systems biology-based ("-omics") techniques in the 21st century, there has been a massive expansion of published data relevant to virtually every physiological question. The authors have developed a large-scale data integration approach based on the application of Bayes'' theorem. In the current work, they integrated 12 different -omics data sets to identify the transcription factors most likely to mediate vasopressin-dependent regulation of transcription of the aquaporin-2 gene.

Deletion of Alox15 improves kidney dysfunction and inhibits fibrosis by increased PGD2 in the kidney

BACKGROUND

Lipid-metabolizing enzymes and their metabolites affect inflammation and fibrosis, but their roles in chronic kidney disease (CKD) have not been completely understood.

METHODS

To clarify their role in CKD, we measured the mRNA levels of major lipid-metabolizing enzymes in 5/6 nephrectomized (Nx) kidneys of C57BL/6 J mice. Mediator lipidomics was performed to reveal lipid profiles of CKD kidneys.

RESULTS

In 5/6 Nx kidneys, both mRNA and protein levels of Alox15 were higher when compared with those in sham kidneys. With respect to in situ hybridization, the mRNA level of Alox15 was higher in renal tubules of 5/6 Nx kidneys. To examine the role of Alox15 in CKD pathogenesis, we performed 5/6 Nx on Alox15-/- mice. Alox15-/- CKD mice exhibited better renal functions than wild-type mice. Interstitial fibrosis was also inhibited in Alox15-/- CKD mice. Mediator lipidomics revealed that Alox15-/- CKD mouse kidneys had significantly higher levels of PGD2 than the control. To investigate the effects of PGD2 on renal fibrosis, we administered PGD2 to TGF-β1-stimulated NRK-52E cells and HK-2 cells, which lead to a dose-dependent suppression of type I collagen and αSMA in both cell lines.

CONCLUSION

Increased PGD2 in Alox15-/- CKD mouse kidneys could inhibit fibrosis, thereby resulting in CKD improvement. Thus, Alox15 inhibition and PGD2 administration may be novel therapeutic targets for CKD.

Association of residual gastric acid secretion with persistent symptoms in gastroesophageal reflux disease patients receiving standard-dose proton pump inhibitor therapy

BACKGROUND

Although a third of gastroesophageal reflux disease (GERD) patients are refractory to proton pump inhibitor (PPI) therapy, the underlying mechanism of the refractoriness remains unclear. We compared the level of gastric acid suppression during PPI treatment between responders and non-responders by directly measuring gastric acid secretion in GERD patients taking PPIs.

METHODS

Seventy-five consecutive patients receiving standard-dose PPI therapy for GERD were prospectively recruited, irrespective of persistent GERD symptoms. They were asked about their GERD symptoms using a validated questionnaire, and simultaneously underwent both a routine endoscopic examination and a gastric acid secretory testing using an endoscopic gastrin test. Associations between residual gastric acid secretion during PPI treatment and persistent GERD symptoms were analyzed by a logistic regression analysis.

RESULTS

Overall, 26 of 75 (34.7%) patients were judged to be positive for persistent GERD symptoms. The patients with and without persistent symptoms showed similar gastric acid secretion levels (1.3 [1.3] mEq/10 min vs. 1.4 [2.0] mEq/10 min). Sufficient gastric acid suppression, defined as < 0.6, was not significantly associated with persistent GERD symptoms (odds ratio 1.1, 95% confidence interval 0.40-3.5).

CONCLUSIONS

This study provided solid evidence to support that the gastric acid suppression level during PPI treatment does not differ between patients with and without persistent GERD symptoms. The insignificant role of residual gastric acid in the persistent GERD symptoms suggests that the use of medications other than those that enhance gastric acid inhibitory effects would be an essential approach for the management of PPI-refractory GERD.

Leg raise can detect exercise-induced pulmonary arterial wedge pressure elevation

Background

Exercise-induced elevation of pulmonary arterial wedge pressure (PAWP) may show preclinical or exercise-induced left ventricular diastolic dysfunction. Invasive hemodynamic assessment during provocative maneuvers, like exercise and volume challenge, in these patients allows greater sensitivity to diagnose or exclude HFpEF. The aim of this study was to examine how the leg raise, which is a simple way to increase preload, can detect exercise-induced PAWP elevation.

Methods

Four hundred seventy-nine patients (60±14y.o, mean pulmonary arterial pressure (PAP) 19mmHg, PAWP 8mmHg, CTEPH /IPAH/CTD-PH/SOB unknown reason: 357/56/38/28pts) with near-normal PAP and normal PAWP at rest underwent symptom-limited exercise test using supine cycle ergometer with right heart catheter. Exercise-induced elevation in PAWP of over 20mmHg was defined as exercise-induced elevation group.

Results

ΔPAWP (after leg raise - rest) in the exercise-induced elevation group was significantly higher (6.0±4.1 vs. 2.7±3.9mmHg, p&lt;0.001, in the older (age≥60y.o) group (n=276); 3.4±3.5 vs. 1.9±3.4mmHg, p&lt;0.001, in the younger (age&lt;60y.o) group (n=203)) than that in the non-elevation group after legs raise for cycle ergometer exercise. The area under the ROC curve for ΔPAWP was 0.72 (95% CI: 0.65–0.78) in the older and 0.64 (95% CI: 0.53–0.75) in the younger. In the older, the cut-off value for detect exercise-induced PAWP elevation of ΔPAWP was 4mmHg, with 72% sensitivity and 58% specificity. On the other hand, in the younger, the cut-off value was 3mmHg, with 69% sensitivity and 59% specificity.

Conclusion

Leg raise can easily detect occult left ventricular diastolic dysfunction.

Funding Acknowledgement

Type of funding source: None

Comparison of pulmonary vascular resistance and pulmonary artery compliance during exercise between IPAH and CTEPH with normal pulmonary artery pressure

Background

Pulmonary vascular resistance (PVR) and pulmonary artery compliance (PAC) are inversely related. However, the little is known about dynamics during exercise by disease difference. The aim of this study was to reveal the relationships of PVR and PAC during exercise between idiopathic pulmonary arterial hypertension (IPAH) and chronic thromboembolic pulmonary hypertension (CTEPH) patients.

Methods

Sixty-two IPAH patients (45±9 y.o) and 359 CTEPH patients (63±13 y.o) with normal mean PAP and PAWP at rest underwent symptom-limited exercise test using supine cycle ergometer with right heart catheter.

Results

There were no differences between baseline mean PAP and PAWP in 2 groups, however, cardiac output, SaO2 and SvO2 were lower in CTEPH group. Lower PAC (2.9±1.1 vs. 3.7±1.7 ml/mmHg, p&lt;0.001) and higher PVR (2.3±1.0 vs. 1.9±1.0 wood.unit, p=0.016) were observed in CTEPH group. These trends were also seen at peak exercise. PVR-PAC relationship in CTEPH group was leftward shift compared with IPAH group (Figure 1).

Conclusion

Resting and exercise PVR and PAC in CTEPH patients were worse than those in IPAH patients who had normal PAP and PAWP at rest.

Figure 1

Funding Acknowledgement

Type of funding source: None

Usefulness of peripheral-pressure-directed balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

Background

Balloon pulmonary angioplasty (BPA) in expert center may be considered in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are technically non-operable for pulmonary endarterectomy. BPA based on objective quantitative methods has not been established. The endpoint at BPA sessions has not been clarified yet.

Objectives

The purpose of this study was to investigate the usefulness of BPA according to peripheral pressure measured by pressure wire or catheter.

Methods

This study included consecutive 143 CTEPH who underwent cardiopulmonary exercise test with right heart catheterization after BPA. All patients were divided into 2 groups such as angio-guided (n=47) group or pressure-guidedgroup (n=96). In pressure-guided group, the pulmonary arterial pressure (PAP) proximal and distal to the target lesion and the ratio of the 2 pressures were measured by the pressure wire or catheter. the endpoint was determined to when the pressure ratio of distal to proximal pressures was &gt;0.7 to 0.8 finally. The dilation was stopped when the distal mean PAP after each dilation reached 35 mm Hg and when the baseline mean PAP was &gt;35 mm Hg. Changes of hemodynamic parameters such as PAP and pulmonary vascular resistance (PVR) from baseline, and mean PAP and PVR at peak oxygen consumption, and pulmonary arterial pressure – cardiac output (PA-CO) slope were compared between two groups. All data except changes of hemodynamics from baseline were expressed by median [25th percentile-75th percentile]. Changes of hemodynamics from baseline were expressed by average [95% confidence interval]

Results

The median age and male were 66 [56–72] years old and 35. There were no significant differences in number of sessions and dilated vessels between two groups (Angio-guided group vs. Pressure-guided group: 4 [3–6] vs. 4 [3–5], P&gt;0.05; 19 [12–22] vs. 17 [13–22], P&gt;0.05). Changes of PAP and PVR from baseline in pressure-guided group was significantly higher than in angio-guided groups (Angio-guided group vs. Pressure-guided group; ΔPAP: −19 [−20 to −17] vs. −20 [−21 to −20], P&gt;0.05; ΔPVR: −6.0 [−6.3 to −5.7] vs. −6.6 [−6.8 to −6.3], P&lt;0.01). Mean PAP and PVR at peak oxygen consumption (VO2) and PA-CO slope in pressure-guided group were significantly lower than in angio-guided group (Angio-guided group vs. Pressure-guided group; PAP at VO2: 43 [36–50] vs. 39 [34–43], P&lt;0.05; PVR at VO2: 2.7 [1.9–4.5] vs. 2.2 [1.6–2.9], P&lt;0.01; PA-CO slope: 3.8 [2.1–5.2] vs. 2.9 [1.9–4.0], P&lt;0.05).

Conclusions

Peripheral-pressure-directed BPA can improve hemodynamics at rest and exercise more effectively.

Funding Acknowledgement

Type of funding source: None

Case Report: A Fatal Case of Scrub Typhus Complicated by Heatstroke

A 76-year-old man who had been bathing in a hot spring was taken to the hospital in a coma. PCR assay performed on the eschar revealed a serotype Hirano/Kuroki of Orientia tsutsugamushi. Coexisted heatstroke superimposed on multiple underlying risk factors likely led to a fatal clinical course.

Genetics May Predict Effectiveness of Tolvaptan in Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Tolvaptan is the only therapeutic drug for autosomal dominant polycystic kidney disease (ADPKD). The influence of mutations in polycystic kidney disease 1 and 2 genes (PKD1 and PKD2) on the treatment effects of tolvaptan is not well documented in the literature.

METHODS

We retrospectively evaluated the relationship between genotype and the efficacy of tolvaptan in 18 patients with ADPKD who had been treated at Toranomon Hospital and undergone genetic testing between April 2016 and February 2020.

RESULTS

The annual change in estimated glomerular filtration rate (ΔeGFR/y) from before to after tolvaptan was from a median of -5.5 to -2.5 mL/min/1.73 m2 in the PKD1 truncating group, -3.3 to -2.4 mL/min/1.73 m2 in the PKD1 non-truncating group, -3.1 to -1.6 mL/min/1.73 m2 in the PKD2 group, and -1.9 to -2.6 mL/min/1.73 m2 in the group with no PKD1/2 mutation. The median degrees of improvement of ΔeGFR/y were 2.5 (45%), 0.4 (10%), 0.6 (28%), and -0.7 (-37%) mL/min/1.73 m2, respectively. Compared with the group of patients with any PKD1/2 mutation, the group with no PKD1/2 mutation showed significantly less improvement in ΔeGFR/y with tolvaptan (0.6 vs. -0.7 mL/min/1.73 m2, respectively; p = 0.01) and significantly less improvement in the annual rate of increase in total kidney volume (TKV) with tolvaptan (-6.7 vs. -1.1%, respectively; p = 0.02).

CONCLUSION

Patients with ADPKD and no PKD1/2 mutation showed less improvement in ΔeGFR/y and the annual rate of increase in TKV with tolvaptan. Detecting PKD1/2 mutations may be useful for predicting the effectiveness of tolvaptan.

AB0482 INFLUENCES OF TIME OF INTRODUCTION OF INFLIXIMAB ON THE FUNCTIONAL DISABILITY AND JOB STATUS OF PATIENTS WITH CHRONIC PROGRESSIVE NEURO-BEHCET’S DISEASE

Background:

Chronic progressive neuro-Behcet’s disease (CPNBD) is characterized by progressive neurobehaviour changes leading to disability and death. It has been appreciated that methotrexate is effective for CPNBD. Notably, recent studies have demonstrated that infliximab is effective for patients with CPNBD who had inadequate responses to methotrexate. However, the appropriate timing for introduction of infliximab remains unclear.

Objectives:

The current studies examined the effects of intervals before introduction of infliximab on the functional disability and job status of patients with CPNBD.

Methods:

Eleven patients (8 males, 3 females, ages 35.2±9.3 [mean±SD]), who met the international classification criteria for BD with CPNBD and received infliximab, were retrospectively followed up. The functional disability of the patients was evaluated by Steinbrocker functional classification as is used in rheumatoid arthritis. Correlation between the patients’ functional outcome and the intervals before the introduction of infliximab was analyzed by Spearman’s rank correlation test.

Results:

All the 11 patients had received methotrexate prior to infliximab. The intervals from the onset to the introduction of infliximab and the follow-up periods were 26.6±35.1 months and 65.2±43.6 months [mean±SD], respectively. Among the 11 patients, 9 patients did not show progression after the introduction of infliximab, whereas 2 patients still progressed and lost job. In the latter 2 patients, infliximab had been discontinued before the final follow-up. No patients improved from the functional disability or gained job even after infliximab treatment. The functional disability grades of the patients after the introduction of infliximab were significantly correlated with the intervals from the onset of CPNBD to the introduction of infliximab (r=0.6177, p=0.0476).

Conclusion:

The results indicate that the delay of the introduction of infliximab leads to the irreversible functional disability and job loss of the patients with CPNBD. Thus, it is recommended that infliximab should be administered as soon as possible for the patients with CPNBD with inadequate response to methotrexate.

References:

[1]Kikuchi H, Aramaki K, Hirohata S. Effect of infliximab in progressive Neuro-Behcet’s syndrome.J Neurol Sci2008; 272: 99-105

Disclosure of Interests: :

Shunsei Hirohata Speakers bureau: Tanabe Mitsubishi, Hirotoshi Kikuchi Speakers bureau: Tanabe Mitsubishi, Tetsuji Sawada: None declared, Masataka Kuwana Grant/research support from: Acetelion, Consultant of: Acetelion, Bayer, Chugai, Corbus Pharmaceuticals, CSL Behring and Reata Pharmaceuticals. He was a member of the SENSCIS trial Steering Committee (Boehringer Ingelheim), Yohei Kirino: None declared, Mitsuhiro Takeno Speakers bureau: Esai, Tanabe-Mitsubishi – speaker; Celgene Corporation – advisory board, Yoshiaki Ishigatsubo: None declared

Renal TNFα activates the WNK phosphorylation cascade and contributes to salt-sensitive hypertension in chronic kidney disease

The inappropriate over-activation of the with-no-lysine kinase (WNK)-STE20/SPS1-related proline/alanine-rich kinase (SPAK)-sodium chloride cotransporter (NCC) phosphorylation cascade increases sodium reabsorption in distal kidney nephrons, resulting in salt-sensitive hypertension. Although chronic kidney disease (CKD) is a common cause of salt-sensitive hypertension, the involvement of the WNK phosphorylation cascade is unknown. Moreover, the effect of immune systems on WNK kinases has not been investigated despite the fact that immune systems are important for salt sensitivity. Here we demonstrate that the protein abundance of WNK1, but not of WNK4, was increased at the distal convoluted tubules in the aristolochic acid nephropathy mouse model of CKD. Accordingly, the phosphorylation of both SPAK and NCC was also increased. Moreover, a high-salt diet did not adequately suppress activation of the WNK1-SPAK-NCC phosphorylation cascade in this model, leading to salt-sensitive hypertension. WNK1 also was increased in adenine nephropathy, but not in subtotal nephrectomy, models of CKD. By comparing the transcripts of these three models focusing on immune systems, we hypothesized that tumor necrosis factor (TNF)-α regulates WNK1 protein expression. In fact, TNF-α increased WNK1 protein expression in cultured renal tubular cells by reducing the transcription and protein levels of NEDD4-2 E3-ligase, which degrades WNK1 protein. Furthermore, the TNF-α inhibitor etanercept reversed the reduction of NEDD4-2 expression and upregulation of the WNK1-SPAK-NCC phosphorylation cascade in distal convoluted tubules in vivo in the aristolochic acid nephropathy model. Thus, salt-sensitive hypertension is induced in CKD via activation of the renal WNK1- SPAK-NCC phosphorylation cascade by TNF-α, reflecting a link with the immune system.

Outcome of maintenance systemic chemotherapy with drug-free interval for metastatic urothelial carcinoma

OBJECTIVE

Aiming to achieve long-term disease control, maintenance systemic chemotherapy (MSC) with a 1-3-month drug-free interval is continued in selected patients. We report our experience of MSC for metastatic urothelial carcinoma (UC).

METHODS

Of 228 metastatic UC patients treated with systemic chemotherapy, 40 (17.5%, 40/228) had continuously undergone MSC. Data on the regimen, cycle number, and reason for the discontinuation of MSC were also collected. We analyzed OS from the initiation of MSC until death or the last follow-up, using the log-rank test to assess the significance of differences.

RESULTS

The median number of cycles of chemotherapy was 6, and the responses were CR in 6, PR in 20, SD in 13, and PD in 1 before MSC. Gemcitabine plus CDDP or carboplatin was mainly performed as MSC (70%, 28/40). MSC was repeated quarterly in 30 (75%, 30/40), every two months in 8 (20%, 8/40), and with other intervals in 2 (5%, 2/40). Overall, a median of 3.5 cycles (range: 1-29) of MSC was performed. The reason for the discontinuation of MSC was PD in 24 (60%, 24/40), favorable disease control in 9 (22.5%, 9/40), and myelosuppression in 3 (7.5%, 3/40), and for other reasons in 2 (5%, 2/40). MSC was ongoing in 2 (5%, 2/40). The median OS was 27 months from the initiation of MSC. PS0 (P = 0.0169), the absence of lung metastasis (P = 0.0387), and resection of the primary site (P = 0.0495) were associated with long-term survival after MSC.

CONCLUSIONS

In selected patients, long-term systemic chemotherapy could be performed with a drug-free interval. Our maintenance strategy with cytotoxic drugs may become one of the treatment options for long-term disease control.

Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu-A spinning top-shaped rubble pile

The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present Hayabusa2 observations of Ryugu's shape, mass, and geomorphology. Ryugu has an oblate "spinning top" shape, with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates a high-porosity (>50%) interior. Large surface boulders suggest a rubble-pile structure. Surface slope analysis shows Ryugu's shape may have been produced from having once spun at twice the current rate. Coupled with the observed global material homogeneity, this suggests that Ryugu was reshaped by centrifugally induced deformation during a period of rapid rotation. From these remote-sensing investigations, we identified a suitable sample collection site on the equatorial ridge.

The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of [Formula: see text] years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu's surface supports partial dehydration due to internal heating of the asteroid's parent body.

Genotype-Clinical Correlations in Polycystic Kidney Disease with No Apparent Family History

BACKGROUND

Genetic characteristics of polycystic kidney disease (PKD) patients without apparent family history were reported to be different from those with a positive family history. However, the clinical course of PKD patients with no apparent family history is not well documented in the literature.

METHODS

We evaluated the relationship between genotype and the clinical course of 62 PKD patients with no apparent family history.

RESULTS

The annual decline of renal function was faster in the patients with PKD1/PKD2 mutation (PKD1 truncating [-3.08; 95% CI -5.30 to -0.87, p = 0.007], PKD1 nontruncating [-2.10; -3.82 to -0.38, p = 0.02], and PKD2 [-2.31; -4.40 to -0.23, p = 0.03]) than in the other patients without PKD1/PKD2 mutation. Similar results were obtained after adjustment for gender, age, estimated glomerular filtration rate (eGFR), height-adjusted total kidney volume (TKV), and mean arterial pressure (MAP). There was no significant difference in the annual decline of renal function among the different PKD1/PKD2 groups, but Kaplan-Meier analysis showed that progression to eGFR < 15 mL/min/1.73 m2 was significantly faster in PKD1 truncating group (p = 0.05). The annual rate of TKV increase was larger in the patients with PKD1/PKD2 mutation (PKD1 truncating [4.63; 95% CI 0.62-8.64, p = 0.03], PKD1 nontruncating [3.79; 0.55-7.03, p = 0.02], and PKD2 [2.11; -1.90 to 6.12, p = 0.29]) than in the other patients without PKD1/PKD2 mutation. Similar results were obtained after adjustment for gender, age, eGFR, and MAP.

CONCLUSION

Detection of PKD1/PKD2 mutation, especially PKD1 truncating, is useful for predicting the renal outcome and rate of TKV increase in PKD patients with no apparent family history.

Failure to sense energy depletion may be a novel therapeutic target in chronic kidney disease

The kidneys consume a large amount of energy to regulate volume status and blood pressure and to excrete uremic toxins. The identification of factors that cause energy mismatch in the setting of chronic kidney disease (CKD) and the development of interventions aimed at improving this mismatch are key research imperatives. Although the critical cellular energy sensor 5'-adenosine monophosphate (AMP)-activated protein kinase (AMPK) is known to be inactivated in CKD, the mechanism of AMPK dysregulation is unknown. In a mouse model of CKD, metabolome analysis confirmed a decrease in AMPK activation in the kidneys despite a high AMP: ATP ratio, suggesting that AMPK did not sense energy depletion. Similar AMPK inactivation was found in heart and skeletal muscle in CKD mice. Several uremic factors were shown to inactivate AMPK in vitro and in ex vivo preparations of kidney tissue. The specific AMPK activator A-769662, which bypasses the AMP sensing mechanism, ameliorated fibrosis and improved energy status in the kidneys of CKD mice, whereas an AMP analog did not. We further demonstrated that a low-protein diet activated AMPK independent of the AMP sensing mechanism, leading to improvement in energy metabolism and kidney fibrosis. These results suggest that a failure to sense AMP is the key mechanism underlying the vicious cycle of energy depletion and CKD progression and direct AMPK activation may be a novel therapeutic approach in CKD.

Generation and characteristics of a novel "double-hit" high grade B-cell lymphoma cell line DH-My6 with MYC/IGH and BCL6/IGH gene arrangements and potential molecular targeted therapies

“Double-hit” lymphoma (DHL) is a high-grade B-cell lymphoma that harbors concurrent MYC and BCL2 or BCL6 rearrangements. Because cases of MYC/BCL6 DHL are uncommon, most reported conclusions have been based on cases of MYC/BCL2 DHL. Lack of experimental MYC/BCL6 DHL models continues to hinder the pathophysiologic and therapeutic investigations of this disorder. We herein describe a novel MYC/BCL6 DHL cell line, designated DH-My6, carrying both the MYC–IGH and BCL6–IGH fusion genes. Interruptions of MYC and BCL6 expressions using short interfering RNAs and chemical inhibitors led to significant attenuation of DH-My6 cell growth. Greater antitumor effects were found when the cells were treated with a combination of MYC and BCL6 inhibitors. Moreover, the PLK1 inhibitor volasertib and the HDAC inhibitor vorinostat synergized strongly when combined with the bromodomain inhibitor JQ1. DH-My6 is a new well-validated MYC/BCL6 DHL cell line that will provide a useful model for studies of the pathogenesis and therapeutics for the less common DHL tumor type. The rationale for approaches targeting both MYC and BCL6, and in combination with PLK1 or HDAC inhibitors for superior suppression of the aggressive MYC/BCL6 DHL warrants further in vivo testing in a preclinical model.

Effect of brefelamide on proliferation of 1321N1 human astrocytoma cells induced by glial cell line-derived neurotrophic factor

Malignant gliomas are highly resistant to chemotherapy and radiation and more effective options for treatment are urgently needed. We reported previously that the aromatic amide brefelamide, which is isolated from methanolic extracts of the cellular slime molds Dictyostelium giganteum and D. brefeldianum, hinders cellular proliferation in a glioma model utilizing 1321N1 human astrocytoma cells. Herein, we examined the mechanisms underlying the inhibition of 1321N1 cell proliferation by brefelamide. Glial cell line-derived neurotrophic factor (GDNF) was found to enhance the rate of proliferation of serum-free cultured 1321N1 cells, but did not affect proliferation in PC12 cells. Brefelamide pretreatment inhibited GDNF-induced cell proliferation and expression of rearranged during transfection (RET). GDNF enhanced the phosphorylation of extracellular signal-regulated kinase (ERK), AKT, and c-jun-N-terminal kinase (JNK); however, brefelamide pretreatment inhibited these effects. Brefelamide also reduced the expression of GDNF mRNA and GDNF secretion. Together, the findings from this study indicate that brefelamide inhibits the proliferation of 1321N1 cell via several mechanisms including reduced GDNF receptor expression and GDNF secretion, and reduced phosphorylation of ERK, AKT, and JNK.

Metformin increases urinary sodium excretion by reducing phosphorylation of the sodium-chloride cotransporter

OBJECTIVE

Metformin is an antidiabetic drug that is widely used to treat patients with diabetes mellitus. Recent studies have reported that treatment with metformin not only improved blood glucose levels but also reduced blood pressure. However, it remains unclear how metformin reduces blood pressure. We hypothesized that metformin affects sodium reabsorption in the kidneys.

METHODS

Urinary sodium excretion and expression of renal sodium transporters were examined in 8-week-old male C57BL/6 mice with acute and chronic treatment of metformin. In addition, we examined metformin effects using ex vivo preparations of mice kidney slices.

RESULTS

In this study, we demonstrated that metformin increased urinary sodium excretion by reducing phosphorylation of the thiazide-sensitive Na-Cl cotransporter (NCC) in acute and chronic metformin administration. We also confirmed reduction of phosphorylated NCC in an ex vivo study. The activity of other renal sodium transporters, such as NKCC2, ENaC, and NHE3 did not show significant changes. WNK-OSR1/SPAK kinase signals were not involved in this inactivation effect of metformin on NCC.

CONCLUSION

Metformin increased urinary sodium excretion by reducing phosphorylation of NCC, suggesting its role in improving hypertension.

Kidney enlargement and multiple liver cyst formation implicate mutations in PKD1/2 in adult sporadic polycystic kidney disease

Distinguishing autosomal-dominant polycystic kidney disease (ADPKD) from other inherited renal cystic diseases in patients with adult polycystic kidney disease and no family history is critical for correct treatment and appropriate genetic counseling. However, for patients with no family history, there are no definitive imaging findings that provide an unequivocal ADPKD diagnosis. We analyzed 53 adult polycystic kidney disease patients with no family history. Comprehensive genetic testing was performed using capture-based next-generation sequencing for 69 genes currently known to cause hereditary renal cystic diseases including ADPKD. Through our analysis, 32 patients had PKD1 or PKD2 mutations. Additionally, 3 patients with disease-causing mutations in NPHP4, PKHD1, and OFD1 were diagnosed with an inherited renal cystic disease other than ADPKD. In patients with PKD1 or PKD2 mutations, the prevalence of polycystic liver disease, defined as more than 20 liver cysts, was significantly higher (71.9% vs 33.3%, P = .006), total kidney volume was significantly increased (median, 1580.7 mL vs 791.0 mL, P = .027) and mean arterial pressure was significantly higher (median, 98 mm Hg vs 91 mm Hg, P = .012). The genetic screening approach and clinical features described here are potentially beneficial for optimal management of adult sporadic polycystic kidney disease patients.

Privacy-Preserving Hypothesis Testing for Reduced Cancer Risk on Daily Physical Activity

Privacy preserving data mining for medical information is an important issue to guarantee confidentiality of integrated multiple data sets. In this paper, we propose a secured scheme to estimate related risk of cancers accurately and effectively in a privacy-preserving way. We study models to configure the appropriate set of attributes to reduce risk of identity of an individual from being determined. We examine the proposed privacy preserving protocol for encrypted hypothesis test, using actual cohort data supplied by National Cancer Center.

“Mobile Nurse” Platform for Ubiquitous Medicine

Objectives : We introduce “Mobile Nurse" (MN) - an emerging platform for the practice of ubiquitous medicine.

Methods : By implementing in a dynamic setting of daily life the patient care traditionally provided by the clinical nurses on duty, MN aims at integral data collection and shortening the response time to the patient. MN is also capable of intelligent interaction with the patient and is able to learn from the patient's behavior and disease sign evaluation for improved personalized treatment.

Results : In this paper, we outline the most essential concepts around the hardware, software and methodological designs of MN. We provide an example of the implementation, and elaborate on the possible future impact on medical practice and biomedical science research.

Conclusions : The main innovation of MN, setting it apart from current tele-medicine systems, is the ability to integrate the patient's signs and symptoms on site, providing medical professionals with powerfultools to elucidate disease mechanisms, to make proper diagnoses and to prescribe treatment.

Microporous Co@C Nanoparticles Prepared by Dealloying CoAl@C Precursors: Achieving Strong Wideband Microwave Absorption via Controlling Carbon Shell Thickness

Excellent magnetic features make Co-based materials promising candidates as high-performance microwave absorbers. However, it is still a significant challenge for Co-based absorbers to possess high-intensity and broadband absorption simultaneously, owing to the lack of dielectric loss and impedance matching. Herein, microporous Co@C nanoparticles (NPs) with carbon shell thicknesses ranging from 1.8-4.9 nm have been successfully synthesized by dealloying CoAl@C precursors. All of the samples exhibit high microwave absorption performance. The microporous Co@C sample possessing a carbon shell of 1.8 nm exhibits the highest absorption intensity among these samples with a minimum reflection loss (RL) of -141.1 dB, whose absorption bandwidth for RL ≤ -10 dB is 7.3 GHz. As the thickness of the carbon shell increases, the absorption bandwidth of the NPs becomes wider. For the sample with the carbon shell thickness of 4.9 nm, the absorption bandwidth for RL ≤ -10 dB reaches a record high of 13.2 GHz. The outstanding microwave attenuation properties are attributed to the dielectric loss of the carbon shell, the magnetic loss of the Co core, and the cooperation of the core-shell structure and microporous morphology. The strong wideband microwave absorption of the carbon-coated microporous Co NPs highlights their potential applications in microwave absorbing systems.