Publications by authors named "Jung Mi Lim"

17 Publications

  • Page 1 of 1

Molecular architecture of a cylindrical self-assembly at human centrosomes.

Nat Commun 2019 03 11;10(1):1151. Epub 2019 Mar 11.

Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA.

The cell is constructed by higher-order structures and organelles through complex interactions among distinct structural constituents. The centrosome is a membraneless organelle composed of two microtubule-derived structures called centrioles and an amorphous mass of pericentriolar material. Super-resolution microscopic analyses in various organisms revealed that diverse pericentriolar material proteins are concentrically localized around a centriole in a highly organized manner. However, the molecular nature underlying these organizations remains unknown. Here we show that two human pericentriolar material scaffolds, Cep63 and Cep152, cooperatively generate a heterotetrameric α-helical bundle that functions in conjunction with its neighboring hydrophobic motifs to self-assemble into a higher-order cylindrical architecture capable of recruiting downstream components, including Plk4, a key regulator for centriole duplication. Mutations disrupting the self-assembly abrogate Plk4-mediated centriole duplication. Because pericentriolar material organization is evolutionarily conserved, this work may offer a paradigm for investigating the assembly and function of centrosomal scaffolds in various organisms.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-019-08838-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6411776PMC
March 2019

Inactivation of the PtdIns(4)P phosphatase Sac1 at the Golgi by HO produced via Ca-dependent Duox in EGF-stimulated cells.

Free Radic Biol Med 2019 02 23;131:40-49. Epub 2018 Nov 23.

Department of Life Science, Ewha Womans University, Seoul 03760, Republic of Korea. Electronic address:

Binding of epidermal growth factor (EGF) to its cell surface receptor induces production of HO, which serves as an intracellular messenger. We have shown that exogenous HO reversibly inactivates the phosphatidylinositol 4-phosphate [PtdIns(4)P] phosphatase Sac1 (suppressor of actin 1) at the Golgi complex of mammalian cells by oxidizing its catalytic cysteine residue and thereby increases both the amount of Golgi PtdIns(4)P and the rate of protein secretion. Here we investigated the effects of EGF on Sac1 oxidation and PtdIns(4)P abundance at the Golgi in A431 cells. EGF induced a transient increase in Golgi PtdIns(4)P as well as a transient oxidation of Sac1 in a manner dependent on elevation of the intracellular Ca concentration and on HO. Oxidation of Sac1 occurred at the Golgi, as revealed with the use of the Golgi-confined Sac1-K2A mutant. Knockdown of Duox enzymes implicated these Ca-dependent members of the NADPH oxidase family as the major source of HO for Sac1 oxidation. Expression of a Golgi-targeted HO probe revealed transient EGF-induced HO production at this organelle. Our findings have thus uncovered a previously unrecognized EGF signaling pathway that links intracellular Ca mobilization to events at the Golgi including Duox activation, HO production, Sac1 oxidation, and PtdIns(4)P accumulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.freeradbiomed.2018.11.021DOI Listing
February 2019

Accumulation of PtdIns(4)P at the Golgi mediated by reversible oxidation of the PtdIns(4)P phosphatase Sac1 by HO.

Free Radic Biol Med 2019 01 16;130:426-435. Epub 2018 Nov 16.

Yonsei Biomedical Research Institute, Yonsei University, Seoul 03722, Republic of Korea. Electronic address:

Phosphatidylinositol 4-phosphate [PtdIns(4)P] plays a key role in the biogenesis of transport vesicles at the Golgi complex by recruiting coat proteins and their accessory factors. The PtdIns(4)P content of the Golgi is determined by the concerted action of PtdIns 4-kinase (PI4K) and PtdIns(4)P phosphatase enzymes. Sac1 (suppressor of actin 1) is the major PtdIns(4)P phosphatase and is localized to the Golgi and endoplasmic reticulum. The targeting of both PI4Ks and Sac1 to the Golgi membrane is extensively regulated, as is the catalytic activity of PI4Ks at the Golgi. However, regulation of the catalytic activity of Sac1 has been largely unexplored. Here we show that Sac1undergoes reversible inactivation in mammalian cells when its catalytic Cys residue is oxidized by exogenous HO to form an intramolecular disulfide with Cys. The oxidative inactivation of Sac1 results in the accumulation of PtdIns(4)P at the Golgi, with this effect also being supported by the HO-induced activation of p38 mitogen-activated protein kinase (MAPK), which was previously shown to promote the translocation of Sac1 from the Golgi to the endoplasmic reticulum. The increase in Golgi PtdIns(4)P due to Sac1 inactivation, however, is faster than that due to Sac1 translocation. Exposure of cells to HO also increased membrane protein trafficking from the Golgi to the plasma membrane as well as protein secretion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.freeradbiomed.2018.11.008DOI Listing
January 2019

Myristoylated methionine sulfoxide reductase A is a late endosomal protein.

J Biol Chem 2018 05 28;293(19):7355-7366. Epub 2018 Mar 28.

Laboratory of Biochemistry, NHLBI, National Institutes of Health, Bethesda, Maryland 20892. Electronic address:

Methionine residues in proteins provide antioxidant defense by reacting with oxidizing species, which oxidize methionine to methionine sulfoxide. Reduction of the sulfoxide back to methionine is catalyzed by methionine sulfoxide reductases, essential for protection against oxidative stress. The nonmyristoylated form of methionine sulfoxide reductase A (MSRA) is present in mitochondria, whereas the myristoylated form has been previously reported to be cytosolic. Despite the importance of MSRA in antioxidant defense, its binding partners and substrates have not been identified. Starting with a protein array, and followed by immunoprecipitation experiments, colocalization studies, and subcellular fractionation, we identified the late endosomal protein, StAR-related lipid transfer domain-containing 3 (STARD3), as a binding partner of myristoylated MSRA, but not of nonmyristoylated MSRA. STARD3 is known to have both membrane-binding and cytosolic domains that are important in STARD3-mediated transport of cholesterol from the endoplasmic reticulum to the endosome. We found that the STARD3 cytosolic domain localizes MSRA to the late endosome. We propose that the previous conclusion that myristoylated MSRA is strictly a cytosolic protein is artifactual and likely due to vigorous overexpression of MSRA. We conclude that myristoylated MSRA is a late endosomal protein that may play a role in lipid metabolism or may protect endosomal proteins from oxidative damage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1074/jbc.RA117.000473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5950012PMC
May 2018

Methionine in Proteins: It's Not Just for Protein Initiation Anymore.

Neurochem Res 2019 Jan 11;44(1):247-257. Epub 2018 Jan 11.

Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, Bethesda, MD, 20892-8012, USA.

Methionine in proteins is often thought to be a generic hydrophobic residue, functionally replaceable with another hydrophobic residue such as valine or leucine. This is not the case, and the reason is that methionine contains sulfur that confers special properties on methionine. The sulfur can be oxidized, converting methionine to methionine sulfoxide, and ubiquitous methionine sulfoxide reductases can reduce the sulfoxide back to methionine. This redox cycle enables methionine residues to provide a catalytically efficient antioxidant defense by reacting with oxidizing species. The cycle also constitutes a reversible post-translational covalent modification analogous to phosphorylation. As with phosphorylation, enzymatically-mediated oxidation and reduction of specific methionine residues functions as a regulatory process in the cell. Methionine residues also form bonds with aromatic residues that contribute significantly to protein stability. Given these important functions, alteration of the methionine-methionine sulfoxide balance in proteins has been correlated with disease processes, including cardiovascular and neurodegenerative diseases. Methionine isn't just for protein initiation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11064-017-2460-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6446232PMC
January 2019

Control of the pericentrosomal H2O2 level by peroxiredoxin I is critical for mitotic progression.

J Cell Biol 2015 Jul;210(1):23-33

Yonsei Biomedical Research Institute, Yonsei University, Seoul 120-749, South Korea

Proteins associated with the centrosome play key roles in mitotic progression in mammalian cells. The activity of Cdk1-opposing phosphatases at the centrosome must be inhibited during early mitosis to prevent premature dephosphorylation of Cdh1-an activator of the ubiquitin ligase anaphase-promoting complex/cyclosome-and the consequent premature degradation of mitotic activators. In this paper, we show that reversible oxidative inactivation of centrosome-bound protein phosphatases such as Cdc14B by H2O2 is likely responsible for this inhibition. The intracellular concentration of H2O2 increases as the cell cycle progresses. Whereas the centrosome is shielded from H2O2 through its association with the H2O2-eliminating enzyme peroxiredoxin I (PrxI) during interphase, the centrosome-associated PrxI is selectively inactivated through phosphorylation by Cdk1 during early mitosis, thereby exposing the centrosome to H2O2 and facilitating inactivation of centrosome-bound phosphatases. Dephosphorylation of PrxI by okadaic acid-sensitive phosphatases during late mitosis again shields the centrosome from H2O2 and thereby allows the reactivation of Cdk1-opposing phosphatases at the organelle.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1083/jcb.201412068DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4493999PMC
July 2015

Selective inhibition of the function of tyrosine-phosphorylated STAT3 with a phosphorylation site-specific intrabody.

Proc Natl Acad Sci U S A 2014 Apr 14;111(17):6269-74. Epub 2014 Apr 14.

Division of Life and Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, and Global Top 5 Research Program, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 120-750, Korea.

Signal transducer and activator of transcription 3 (STAT3) is a multifunctional protein that participates in signaling pathways initiated by various growth factors and cytokines. It exists in multiple forms including those phosphorylated on Tyr(705) (pYSTAT3) or Ser(727) (pSSTAT3) as well as the unphosphorylated protein (USTAT3). In addition to the canonical transcriptional regulatory role of pYSTAT3, both USTAT3 and pSSTAT3 function as transcriptional regulators by binding to distinct promoter sites and play signaling roles in the cytosol or mitochondria. The roles of each STAT3 species in different biological processes have not been readily amenable to investigation, however. We have now prepared an intrabody that binds specifically and with high affinity to the tyrosine-phosphorylated site of pYSTAT3. Adenovirus-mediated expression of the intrabody in HepG2 cells as well as mouse liver blocked both the accumulation of pYSTAT3 in the nucleus and the production of acute phase response proteins induced by interleukin-6. Intrabody expression did not affect the overall accumulation of pSSTAT3 induced by interleukin-6 or phorbol 12-myristate 13-acetate (PMA), the PMA-induced expression of the c-Fos gene, or the PMA-induced accumulation of pSSTAT3 specifically in mitochondria. In addition, it had no effect on interleukin-6-induced expression of the gene for IFN regulatory factor 1, a downstream target of STAT1. Our results suggest that the engineered intrabody is able to block specifically the downstream effects of pYSTAT3 without influencing those of pSSTAT3, demonstrating the potential of intrabodies as tools to dissect the cellular functions of specific modified forms of proteins that exist as multiple species.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.1316815111DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4035943PMC
April 2014

HBxAPα/Rsf-1-mediated HBx-hBubR1 interactions regulate the mitotic spindle checkpoint and chromosome instability.

Carcinogenesis 2013 Jul 27;34(7):1680-8. Epub 2013 Mar 27.

Department of Biochemistry and Molecular Biology, Ajou University School of Medicine and the Graduate School of Molecular Science and Technology, Ajou University, Suwon, South Korea.

Hepatitis B virus (HBV) X protein (HBx), encoded by the HBV genome, is involved in the development of HBV-mediated liver cancer, whose frequency is highly correlated with chromosomal instability (CIN). We reported previously that HBx induces mitotic checkpoint dysfunction by targeting the human serine/threonine kinase BubR1 (hBubR1). However, the underlying mechanism remained unresolved. Here, we show that HBx protein-associated protein α (HBxAPα)/Rsf-1 associates with hBubR1 and HBx in the chromatin fraction during mitosis. Depletion of HBxAPα/Rsf-1 abolished the interaction between HBx and hBubR1, indicating that HBxAPα/Rsf-1 mediates these interactions. Knockdown of HBxAPα/Rsf-1 with small interfering RNA did not affect the recruitment of hBubR1 to kinetochores; however, it did significantly impair HBx targeting to kinetochores. A deletion mutant analysis revealed that two Kunitz domains of HBx, the Cdc20-binding domain of hBubR1 and full-length of HBxAPα/Rsf-1 were essential for these interactions. Thus, binding of HBx to hBubR1, stabilized by HBxAPα/Rsf-1, significantly attenuated hBubR1 binding to Cdc20 and consequently increased the rate of mitotic aberrations. Collectively, our data show that the HBx impairs hBubR1 function and induces CIN through HBxAPα/Rsf-1, providing a novel mechanism for induction of genomic instability by a viral pathogen in hepatocarcinogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/carcin/bgt105DOI Listing
July 2013

Sestrins activate Nrf2 by promoting p62-dependent autophagic degradation of Keap1 and prevent oxidative liver damage.

Cell Metab 2013 Jan 27;17(1):73-84. Epub 2012 Dec 27.

Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Korea.

Sestrins (Sesns) protect cells from oxidative stress. The mechanism underlying the antioxidant effect of Sesns has remained unknown, however. The Nrf2-Keap1 pathway provides cellular defense against oxidative stress by controlling the expression of antioxidant enzymes. We now show that Sesn1 and Sesn2 interact with the Nrf2 suppressor Keap1, the autophagy substrate p62, and the ubiquitin ligase Rbx1 and that the antioxidant function of Sesns is mediated through activation of Nrf2 in a manner reliant on p62-dependent autophagic degradation of Keap1. Sesn2 was upregulated in the liver of mice subjected to fasting or subsequent refeeding with a high-carbohydrate, fat-free diet, whereas only refeeding promoted Keap1 degradation and Nrf2 activation, because only refeeding induced p62 expression. Ablation of Sesn2 blocked Keap1 degradation and Nrf2 activation induced by refeeding and thereby increased the susceptibility of the liver to oxidative damage resulting from the acute stimulation of lipogenesis associated with refeeding.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cmet.2012.12.002DOI Listing
January 2013

Function of Ahnak protein in aortic smooth muscle cell migration through Rac activation.

Cardiovasc Res 2013 Feb 5;97(2):302-10. Epub 2012 Oct 5.

Department of Life Science, Ewha Womans University, 11-1 Daehyun-Dong, Seodaemoon-Gu, Seoul 120-750, Korea.

Aims: Ahnak protein acts as a scaffold protein networking phospholipase C-γ and protein kinase C-α, which subsequently stimulate an extracellular signal-regulated kinase (Erk) pathway. In mouse aortic smooth muscle cells (ASMCs), the activation of the signalling cascade ultimately promotes the cell migration through an unknown mechanism. We aimed to dissect the Ahnak-mediated cell signalling network involved in the migration of ASMCs.

Methods And Results: Migration of ASMCs from wild-type mice was significantly increased by platelet-derived growth factor (PDGF) stimulation in transwell chamber and wound-healing assays, whereas migration of ASMCs from Ahnak knockout mice was reduced. Consistently, stimulation of wild-type ASMCs with PDGF resulted in Rac activation-mediated lamellipodial protrusion in migrating cells. In contrast, Ahnak knockout ASMCs displayed lower activation of Rac in response to PDGF and slow lamellipodial protrusion rate and cell migration. Ahnak signalling complex was analysed by immunoprecipitation with antibody to p21-activated protein kinase (PAK). Ahnak protein was shown to function as the signalling scaffold interacting with the multiple protein complex of Erk, PAK, and p21-activated kinase-interacting exchange factor β. The proposed role of Ahnak in cell migration was examined using a restenosis model in which the carotid arteries of mice were subjected to post-ligation injury. We show neointimal formation and SMC migration after ligation injury in Ahnak knockout mice were significantly retarded compared with wild-type mice.

Conclusion: Ahnak protein plays an important scaffolding function connecting Erk and Rac activation in PDGF-dependent migration of ASMC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cvr/cvs311DOI Listing
February 2013

A fluorescence turn-on H2O2 probe exhibits lysosome-localized fluorescence signals.

Chem Commun (Camb) 2012 Jun 26;48(44):5449-51. Epub 2012 Apr 26.

Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, Korea.

A new fluorescence turn-on probe that responds exclusively to H(2)O(2) exhibits subcellular localized fluorescence staining of lysosomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c2cc31632cDOI Listing
June 2012

Functionalized Fe3O4 nanoparticles for detecting zinc ions in living cells and their cytotoxicity.

Chemistry 2012 May 19;18(19):5843-7. Epub 2012 Apr 19.

Department of Chemistry and Research Institute of Natural Sciences Gyeongsang National University, Jinju 660-701, Korea.

The zinc tank: A new fluoro-chromogenic chemosensor based on BODIPY-functionalized Fe(3)O(4) nanoparticles (1) has been prepared. Chemoprobe 1 exhibits high selectivity for Zn(2+) over other competing metal ions tested. Moreover, confocal microscopy experiments established that 1 can be used for detecting Zn(2+) levels in living cells (see figure).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/chem.201200294DOI Listing
May 2012

A highly sensitive and selective turn-on fluorogenic and chromogenic sensor based on BODIPY-functionalized magnetic nanoparticles for detecting lead in living cells.

Chemistry 2010 Oct 27;16(38):11549-53. Epub 2010 Aug 27.

Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju 660-701, Korea.

A new fluoro-chromogenic chemosensor based on BODIPY-functionalized Fe(3)O(4)@SiO(2) core/shell nanoparticles 1 has been prepared. Chemosensor 1 exhibits a high affinity and selectivity for Pb(2+) over competing metal ions tested. Moreover, confocal microscopy, and flow cytometry experiments established that 1 can be used for detecting Pb(2+) levels within living cell.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/chem.201001772DOI Listing
October 2010

BODIPY-functionalized gold nanoparticles as a selective fluoro-chromogenic chemosensor for imaging Cu2+ in living cells.

Analyst 2010 Aug 23;135(8):2022-7. Epub 2010 Jun 23.

Department of Chemistry and Research Institute of Natural Science, Gyeongsang National University, Jinju 660-701, S. Korea.

A new fluoro-chromogenic chemosensor based on BODIPY-functionalized gold nanoparticles 1 is prepared. Addition of Cu(2+) ions to aqueous solutions of 1 gave an instantaneous color change along with a blue-shift of the absorption band and quenching of the emission spectrum at room temperature. The chemosensor 1 exhibits a high affinity and selectivity for Cu(2+) over competing metal ions tested. Moreover, confocal microscopy experiments establish that 1 can be used for detecting Cu(2+) levels within living cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c0an00129eDOI Listing
August 2010

Lysine-functionalized silver nanoparticles for visual detection and separation of histidine and histidine-tagged proteins.

Langmuir 2010 Feb;26(3):2181-5

Department of Chemistry and Research Institute of Natural Sciences and Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea.

A new chromogenic chemosensor based on lysine-functionalized silver nanoparticles 1 was prepared and characterized by transmission electron microscopy (TEM), Fourier transform Raman, and ultraviolet-visible (UV-vis) spectroscopy. The color changes of nanoparticles 1 in the absence and the presence of metal ion were observed upon addition of various amino acids and proteins in aqueous solution. Among the various amino acids, the sensor 1 in the absence of metal ion shows a novel colorimetric sensor with capability to probe histidine and histidine-tagged proteins. On the other hand, the color changes of 1 in the presence of metal ions such as KCl or NiCl(2) did not occur with any amino acids. Therefore, the sensor 1 in the absence of metal ion responds selectively to histidine, a response which can be attributed to its aggregation induced by histidine with high numbers of electrostatic interactions. This highly selective sensor 1 allows a rapid quantitative assay of histidine to concentrations as low as 5.0 microM, providing a new tool for the direct measurement of histidine and histidine-tagged proteins in vitro system. Furthermore, we examined the effect of pH on absorbance (A(520)) of 1 in the presence of histidine (pH 4-12). The absorbance under basic conditions was higher than that under acidic or neutral conditions, in accord with the stronger aggregation of 1 with histidine by electrostatic interaction between the carboxylate anion of 1 and ammonium protons of histidine under basic conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/la9026865DOI Listing
February 2010

Cu,Zn-superoxide dismutase is an intracellular catalyst for the H(2)O(2)-dependent oxidation of dichlorodihydrofluorescein.

Mol Cells 2006 Feb;21(1):161-5

Department of Biochemistry, Kangwon National University, Chunchon 200-701, Korea.

Dichlorodihydrofluorescein (DCFH(2)) is a widely used probe for intracellular H(2)O(2). However, H(2)O(2) can oxidize DCFH(2) only in the presence of a catalyst, whose identity in cells has not been clearly defined. We compared the peroxidase activity of Cu,Zn-superoxide dismutase (CuZnSOD), cytochrome c, horseradish peroxidase (HRP), Cu(2+), and Fe(3+) under various condi-tions to identify an intracellular catalyst. Enormous increase by bicarbonate in the rate of DCFH(2) oxidation distinguished CuZnSOD from cytochrome c and HRP. Cyanide inhibited the reaction catalyzed by CuZnSOD but accelerated that by Cu(2+) and Fe(3+). Oxidation of DCFH(2) by H(2)O(2) in the presence of a cell lys-ate was also enhanced by bicarbonate and inhibited by cyanide. Confocal microscopy of H(2)O(2)-treated cells showed enhanced DCF fluorescence in the presence of bicarbonate and attenuated fluorescence for the cells pre-incubated with KCN. Moreover, DCF fluorescence was intensified in CuZnSOD-transfected HaCaT and RAW 264.7 cells. We propose that CuZnSOD is a potential intracellular catalyst for the H(2)O(2)-dependent oxidation of DCFH(2).
View Article and Find Full Text PDF

Download full-text PDF

Source
February 2006

Expression of endothelial nitric oxide synthase in developing rat kidney.

Am J Physiol Renal Physiol 2005 Apr 30;288(4):F694-702. Epub 2004 Nov 30.

Dept. of Internal Medicine, Div. of Nephrology, Kangbuk Samsung Hospital, Sungkyunkwan Univ. School of Medicine, 108, Pyung-Dong, Jongro-Ku, Seoul 110-746, Korea.

Endothelium-derived nitric oxide (NO) is synthesized within the developing kidney and may play a crucial role in the regulation of renal hemodynamics. The purpose of this study was to establish the expression and intrarenal localization of the NO-synthesizing enzyme endothelial NO synthase (eNOS) during kidney development. Rat kidneys from 14 (E14)-, 16 (E16)-, 18 (E18)-, and 20-day-old (E20) fetuses and 1 (P1)-, 3 (P3)-, 7 (P7)-, 14 (P14)-, and 21-day-old (P21) pups were processed for immunocytochemical and immunoblot analysis. In fetal kidneys, expression of eNOS was first observed in the endothelial cells of the undifferentiated intrarenal capillary network at E14. At E16, strong eNOS immunoreactivity was observed in the endothelial cells of renal vesicles, S-shaped bodies (stage II glomeruli), and stage III glomeruli at the corticomedullary junction. At E18-20, early-stage developing glomeruli located in the subcapsular region showed less strong eNOS immunoreactivity than those of E16. The eNOS-positive immature glomeruli were observed in the nephrogenic zone until 7 days after birth. In fetal kidneys, eNOS was also expressed in the medulla in the endothelial cells of the capillaries surrounding medullary collecting ducts. After birth, eNOS immunostaining gradually increased in the developing vascular bundles and peritubular capillaries in the medulla and was highest at P21. Surprisingly, eNOS was also expressed in proximal tubules, in the endocytic vacuolar apparatus, only at P1. The strong expression of eNOS in the early stages of developing glomeruli and vasculature suggests that eNOS may play a role in regulating renal hemodynamics of the immature kidney.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/ajprenal.00085.2004DOI Listing
April 2005