Maternal separation diminishes {alpha}-adrenergic receptor density and function in renal vasculature from male Wistar-Kyoto rats
Adult rats exposed to maternal separation (MatSep) are normotensive but display lower glomerular filtration rate and increased renal neuroadrenergic drive. The aim of this study was to determine the renal α-adrenergic receptor density and the renal vascular responsiveness to adrenergic stimulation in male rats exposed to MatSep. In addition, baroreflex sensitivity was assessed to determine a component of neural control of the vasculature. Using tissue collected from 4-mo-old MatSep and control rats, α1-adrenergic receptors (α1-ARs) were measured in renal cortex and isolated renal vasculature using recepto...
Source: AJP: Renal Physiology - July 1, 2017 Category: Urology & Nephrology Authors: Loria, A. S., Osborn, J. L. Tags: RESEARCH ARTICLE Source Type: research
Identification of {beta}-catenin-interacting proteins in nuclear fractions of native rat collecting duct cells
The gene encoding the aquaporin-2 water channel is regulated transcriptionally in response to vasopressin. In the renal collecting duct, vasopressin stimulates the nuclear translocation and phosphorylation (at Ser552) of β-catenin, a multifunctional protein that acts as a transcriptional coregulator in the nucleus. The purpose of this study was to identify β-catenin-interacting proteins that might be involved in transcriptional regulation in rat inner medullary collecting duct (IMCD) cells, using experimental and computational approaches. We used a standard chromatin immunoprecipitation procedure coupled to mass ...
Source: AJP: Renal Physiology - July 1, 2017 Category: Urology & Nephrology Authors: Hwang, J. R., Chou, C.-L., Medvar, B., Knepper, M. A., Jung, H. J. Tags: RESEARCH ARTICLE Source Type: research
Intrarenal signaling mediated by CCK plays a role in salt intake-induced natriuresis
The natriuretic hormone CCK exhibits its gene transcripts in total kidney extracts. To test the possibility of CCK acting as an intrarenal mediator of sodium excretion, we examined mouse kidneys by 1) an in situ hybridization technique for CCK mRNA in animals fed a normal- or a high-sodium diet; 2) immuno-electron microscopy for the CCK peptide, 3) an in situ hybridization method and immunohistochemistry for the CCK-specific receptor CCKAR; 4) confocal image analysis of receptor-mediated Ca2+ responses in isolated renal tubules; and 5) metabolic cage experiments for the measurement of urinary sodium excretion in high-salt-...
Source: AJP: Renal Physiology - July 1, 2017 Category: Urology & Nephrology Authors: Takahashi-Iwanaga, H., Kimura, S., Konno, K., Watanabe, M., Iwanaga, T. Tags: RESEARCH ARTICLE Source Type: research
Physiopathological implications of P2X1 and P2X7 receptors in regulation of glomerular hemodynamics in angiotensin II-induced hypertension
Deleterious effects of purinergic P2X1 and P2X7 receptors (P2XRs) in ANG II-dependent hypertension include increased renal vascular resistance, and impaired autoregulation and pressure natriuresis. However, their specific effects on the determinants of glomerular hemodynamics remain incompletely delineated. To investigate the P2XR contributions to altered glomerular hemodynamics in hypertension, the effects of acute blockade of P2X1R, P2X7R, and P2X4R with NF449, A438079, and PSB12054, respectively, were evaluated in ANG II-infused rats (435 ng·kg–1·min–1). P2X1R or P2X7R blockade reduced afferent...
Source: AJP: Renal Physiology - July 1, 2017 Category: Urology & Nephrology Authors: Franco, M., Bautista-Perez, R., Cano-Martinez, A., Pacheco, U., Santamaria, J., del Valle Mondragon, L., Perez-Mendez, O., Navar, L. G. Tags: RESEARCH ARTICLE Source Type: research
{beta}-Arrestin-biased AT1R stimulation promotes extracellular matrix synthesis in renal fibrosis
In this study we investigated the role of β-arrestins in regulating extracellular matrix (ECM) synthesis in renal fibrosis. The rat kidney fibroblast cell line (NRK-49F) was treated with the β-arrestin biased agonist [1-sar, 4, 8-ile]angiotensin II (SII), which does not initiate AT1R-G protein signaling. The cells were transfected with recombinant adenoviruses expressing β-arrestin-2 gene or small-interfering RNA (siRNA) targeting β-arrestin-2. The unilateral ureteral obstruction (UUO) model was used in vivo. mRNA and protein levels of β-arrestin-2, not β-arrestin-1, were significantly upregul...
Source: AJP: Renal Physiology - July 1, 2017 Category: Urology & Nephrology Authors: Wang, Y., Huang, J., Liu, X., Niu, Y., Zhao, L., Yu, Y., Zhou, L., Lu, L., Yu, C. Tags: RESEARCH ARTICLE Source Type: research
2017 Young Investigator Award of the American Physiological Society Renal Section
(Source: AJP: Renal Physiology)
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Tags: ANNOUNCEMENT Source Type: research
2017 Robert W. Berliner Award for Excellence in Renal Physiology
(Source: AJP: Renal Physiology)
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Tags: ANNOUNCEMENT Source Type: research
2017 Carl Gottschalk Award Distinguished Lecturer
(Source: AJP: Renal Physiology)
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Tags: ANNOUNCEMENT Source Type: research
Wolf-Hirschhorn syndrome candidate 1-like 1 epigenetically regulates nephrin gene expression
In conclusion, our results demonstrate that WHSC1L1-L acts as a histone methyltransferase in podocytes and regulates nephrin gene expression, which may in turn contribute to the integrity of the slit diaphragm of the glomerular filtration barrier. (Source: AJP: Renal Physiology)
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Authors: Ito, Y., Katayama, K., Nishibori, Y., Akimoto, Y., Kudo, A., Kurayama, R., Hada, I., Takahashi, S., Kimura, T., Fukutomi, T., Katada, T., Suehiro, J., Beltcheva, O., Tryggvason, K., Yan, K. Tags: RESEARCH ARTICLE Source Type: research
An intracellular matrix metalloproteinase-2 isoform induces tubular regulated necrosis: implications for acute kidney injury
Acute kidney injury (AKI) causes severe morbidity, mortality, and chronic kidney disease (CKD). Mortality is particularly marked in the elderly and with preexisting CKD. Oxidative stress is a common theme in models of AKI induced by ischemia-reperfusion (I-R) injury. We recently characterized an intracellular isoform of matrix metalloproteinase-2 (MMP-2) induced by oxidative stress-mediated activation of an alternate promoter in the first intron of the MMP-2 gene. This generates an NH2-terminal truncated MMP-2 (NTT-MMP-2) isoform that is intracellular and associated with mitochondria. The NTT-MMP-2 isoform is expressed in ...
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Authors: Ceron, C. S., Baligand, C., Joshi, S., Wanga, S., Cowley, P. M., Walker, J. P., Song, S. H., Mahimkar, R., Baker, A. J., Raffai, R. L., Wang, Z. J., Lovett, D. H. Tags: RESEARCH ARTICLE Source Type: research
Role of intratubular pressure during the ischemic phase in acute kidney injury
Acute kidney injury (AKI) induced by clamping of renal vein or pedicle is more severe than clamping of artery, but the mechanism has not been clarified. In the present study, we tested our hypothesis that increased proximal tubular pressure (Pt) during the ischemic phase exacerbates kidney injury and promotes the development of AKI. We induced AKI by bilateral clamping of renal arteries, pedicles, or veins for 18 min at 37°C, respectively. Pt during the ischemic phase was measured with micropuncture. We found that higher Pt was associated with more severe AKI. To determine the role of Pt during the ischemic phase on th...
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Authors: Wei, J., Song, J., Jiang, S., Zhang, G., Wheeler, D., Zhang, J., Wang, S., Lai, E. Y., Wang, L., Buggs, J., Liu, R. Tags: RESEARCH ARTICLE Source Type: research
Gremlin1 plays a key role in kidney development and renal fibrosis
Gremlin1 (Grem1), an antagonist of bone morphogenetic proteins, plays a key role in embryogenesis. A highly specific temporospatial gradient of Grem1 and bone morphogenetic protein signaling is critical to normal lung, kidney, and limb development. Grem1 levels are increased in renal fibrotic conditions, including acute kidney injury, diabetic nephropathy, chronic allograft nephropathy, and immune glomerulonephritis. We demonstrate that a small number of grem1–/– whole body knockout mice on a mixed genetic background (8%) are viable, with a single, enlarged left kidney and grossly normal histology. The grem1&nd...
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Authors: Church, R. H., Ali, I., Tate, M., Lavin, D., Krishnakumar, A., Kok, H. M., Hombrebueno, J. R., Dunne, P. D., Bingham, V., Goldschmeding, R., Martin, F., Brazil, D. P. Tags: RESEARCH ARTICLE Source Type: research
Chronic kidney disease induces autophagy leading to dysfunction of mitochondria in skeletal muscle
This study examines whether autophagy-mediated proteolysis contributes to CKD-induced muscle wasting. We tested autophagy in the muscle of CKD mice with plantaris muscle overloading to mimic resistance exercise or with acupuncture plus low-frequency electrical stimulation (Acu/LFES) treatment. In CKD muscle, Bnip3, Beclin-1, and LC3II mRNAs and proteins were increased compared with those in control muscle, indicating autophagosome-lysosome formation induction. Acu/LFES suppressed the CKD-induced upregulation of autophagy. However, overloading increased autophagy-related proteins in normal and CKD muscle. Serum from uremic ...
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Authors: Su, Z., Klein, J. D., Du, J., Franch, H. A., Zhang, L., Hassounah, F., Hudson, M. B., Wang, X. H. Tags: RESEARCH ARTICLE Source Type: research
Inhibition of ROMK blocks macula densa tubuloglomerular feedback yet causes renal vasoconstriction in anesthetized rats
In conclusion, blockade of ROMK or Na+-K+-2Cl– transport inhibits TGF yet increases renal vascular resistance. The renal vasoconstriction was independent of volume depletion, blood pressure, TGF, or PPT. (Source: AJP: Renal Physiology)
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Authors: Araujo, M., Welch, W. J., Zhou, X., Sullivan, K., Walsh, S., Pasternak, A., Wilcox, C. S. Tags: RESEARCH ARTICLE Source Type: research
Effects of childbirth on podocyturia in women with normotensive, uncomplicated pregnancies
This study aimed to test the hypothesis that parturition induces a temporal increase in podocyturia monitored by podocyte-specific protein podocin mRNA expression levels (Pod-mRNA). A total of 105 urine specimens, consisting of 43 and 62 from 18 and 20 otherwise healthy women with vaginal delivery (VD) and elective cesarean delivery (ECS), respectively, were studied. Determination of urine protein and creatinine (Cr) concentrations and quantitative analyses of Pod-mRNA, nephrin mRNA (Nep-mRNA), synaptopodin mRNA (Syn-mRNA), and aquaporin 2 mRNA expression were performed using RT-PCR in pelleted urine samples. Levels of mRN...
Source: AJP: Renal Physiology - June 4, 2017 Category: Urology & Nephrology Authors: Furuta, I., Zhai, T., Umazume, T., Ishikawa, S., Nakagawa, K., Kojima, T., Yamada, T., Morikawa, M., Minakami, H. Tags: RESEARCH ARTICLE Source Type: research
