Multiple Roles of the SO[Formula]/Cl⁻/OH⁻ Exchanger Protein Slc26a2 in Chondrocyte Functions

Park, Meeyoung,Ohana, Ehud,Choi, Soo Young,Lee, Myeong-Sok,Park, Jong Hoon,Muallem, Shmuel American Society for Biochemistry and Molecular Bi 2014 The Journal of biological chemistry Vol.289 No.4

<P>Mutations in the SO[Formula]/Cl<SUP>−</SUP>/OH<SUP>−</SUP> exchanger Slc26a2 cause the disease diastrophic dysplasia (DTD), resulting in aberrant bone development and, therefore, skeletal deformities. DTD is commonly attributed to a lack of chondrocyte SO[Formula] uptake and proteoglycan sulfation. However, the skeletal phenotype of patients with DTD is typified by reduction in cartilage and osteoporosis of the long bones. Chondrocytes of patients with DTD are irregular in size and have a reduced capacity for proliferation and terminal differentiation. This raises the possibility of additional roles for Slc26a2 in chondrocyte function. Here, we examined the roles of Slc26a2 in chondrocyte biology using two distinct systems: mouse progenitor mesenchymal cells differentiated to chondrocytes and freshly isolated mouse articular chondrocytes differentiated into hypertrophic chondrocytes. Slc26a2 expression was manipulated acutely by delivery of Slc26a2 or shSlc26a2 with lentiviral vectors. We demonstrate that slc26a2 is essential for chondrocyte proliferation and differentiation and for proteoglycan synthesis. Slc26a2 also regulates the terminal stage of chondrocyte cell size expansion. These findings reveal multiple roles for Slc26a2 in chondrocyte biology and emphasize the importance of Slc26a2-mediated protein sulfation in cell signaling, which may account for the complex phenotype of DTD.</P>

CRETACEOUS PALAEOBOTANY AND PHYTOGEOGRAPHY IN EASTERN EURASIA

( Tatsuaki Kimura,Tamiko Ohana ) 한국고생물학회 1992 N/A Vol.1 No.-

FOSSIL PLANTS FROM THE LOWER CRETACEOUS MONOBE FORMATION AND UPPER CRETACEOUS IZUMI GROUP, WEST JAPAN

Tatsuaki KIMURA(木村達明),Tamiko OHANA(大花民子) 한국고생물학회 1995 고생물학회지 Vol.11 No.2

A Rare Case of Lymph Node Metastasis from Early Gastric Cancer

Takaaki Yoshikawa,Yoshio Kadokawa,Masaya Ohana,Akihisa Fukuda,Hiroshi Seno 대한소화기내시경학회 2019 Clinical Endoscopy Vol.52 No.4

Gastric cancers that fulfill the Japanese criteria for curative endoscopic resection show a low risk of lymph node (LN) metastasis. Here,we report a case of LN metastasis from early gastric cancer that fulfilled the curative criteria. A 74-year-old Japanese woman wasreferred to our hospital for treatment of early gastric cancer identified at the site of a hyperplastic polyp that had been diagnosed 10years prior to presentation. Contrast-enhanced computed tomography did not show any lymphadenopathy and laparoscopy-assisteddistal gastrectomy was performed. Histopathological examination revealed a predominantly moderately differentiated adenocarcinomathat measured 15 mm in size and was confined to the mucosa. However, a single metastatic regional LN was observed. A few cancercells showed positive staining for alpha-fetoprotein. It should be noted that early gastric cancer can be accompanied by LN metastasiseven if it fulfills the criteria for curative endoscopic resection.

Friction and wear of DLC films in water environment

Akihiro Tanaka,Masahiro Suzuki,Kazunori Umeda,Tsuguyori Ohana 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.2002 No.10

일본 北海道 에조(蝦夷)층근 上部 (백악계)의 毬果目植物

박순옥(Sun-Ok Park),大花民子(Tamiko Ohana),木村達明(Tatsuaki Kimura) 한국고생물학회 2000 고생물학회지 Vol.16 No.2

Convergence of IRBIT, phosphatidylinositol (4,5) bisphosphate, and WNK/SPAK kinases in regulation of the Na⁺-HCO₃⁻ cotransporters family

Hong, Jeong Hee,Yang, Dongki,Shcheynikov, Nikolay,Ohana, Ehud,Shin, Dong Min,Muallem, Shmuel National Academy of Sciences 2013 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.110 No.10

<P>Fluid and HCO<SUB>3</SUB><SUP>−</SUP> secretion is a vital function of secretory epithelia, involving basolateral HCO<SUB>3</SUB><SUP>−</SUP> entry through the Na<SUP>+</SUP>-HCO<SUB>3</SUB><SUP>−</SUP> cotransporter (NBC) NBCe1-B, and luminal HCO<SUB>3</SUB><SUP>−</SUP> exit mediated by cystic fibrosis transmembrane conductance regulator (CFTR) and solute carrier family 26 (SLC26) Cl<SUP>−</SUP>/HCO<SUB>3</SUB><SUP>−</SUP> exchangers. HCO<SUB>3</SUB><SUP>−</SUP> secretion is highly regulated, with the WNK/SPAK kinase pathway setting the resting state and the IRBIT/PP1 pathway setting the stimulated state. However, we know little about the relationships between the WNK/SPAK and IRBIT/PP1 sites in the regulation of the transporters. The first 85 N-terminal amino acids of NBCe1-B function as an autoinhibitory domain. Here we have identified a positively charged module within NBCe1-B(37-65) that is conserved in NBCn1-A and all 20 members of the NBC superfamily except NBCe1-A. This module is required for the interaction and activation of NBCe1-B and NBCn1-A by IRBIT and their regulation by phosphatidylinositol 4,5-bisphosphate (PIP<SUB>2</SUB>). Activation of the transporters by IRBIT and PIP<SUB>2</SUB> is nonadditive but complementary. Phosphorylation of Ser65 mediates regulation of NBCe1-B by SPAK, and phosphorylation of Thr49 is required for regulation by IRBIT and SPAK. Sequence searches using the NBCe1-B regulatory module as a template identified a homologous sequence in the CFTR R domain and Slc26a6 sulfat transporter and antisigma factor antagonist (STAS) domain. Accordingly, the R and STAS domains bind IRBIT, and the R domain is required for activation of CFTR by IRBIT. These findings reveal convergence of regulatory modalities in a conserved domain of the NBC that may be present in other HCO<SUB>3</SUB><SUP>−</SUP> transporters and thus in the regulation of epithelial fluid and HCO<SUB>3</SUB><SUP>−</SUP> secretion.</P>

Intracellular Cl⁻ as a signaling ion that potently regulates Na⁺/HCO3⁻ transporters

Shcheynikov, Nikolay,Son, Aran,Hong, Jeong Hee,Yamazaki, Osamu,Ohana, Ehud,Kurtz, Ira,Shin, Dong Min,Muallem, Shmuel National Academy of Sciences 2015 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.112 No.3

<P>Cl- is a major anion in mammalian cells involved in transport processes that determines the intracellular activity of many ions and plasma membrane potential. Surprisingly, a role of intracellular Cl- (Cl-in(-)) as a signaling ion has not been previously evaluated. Here we report that Cl-in(-) functions as a regulator of cellular Na+ and HCO3- concentrations and transepithelial transport through modulating the activity of several electrogenic Na+-HCO3- transporters. We describe the molecular mechanism(s) of this regulation by physiological Cl-in(-) concentrations highlighting the role of GXXXP motifs in Cl-sensing. Regulation of the ubiquitous Na+-HCO3- co-transport (NBC)e1-B is mediated by two GXXXP-containing sites; regulation of NBCe2-C is dependent on a single GXXXP motif; and regulation of NBCe1-A depends on a cryptic GXXXP motif. In the basal state NBCe1-B is inhibited by high Cl-in(-) interacting at a low affinity GXXXP-containing site. IP3 receptor binding protein released with IP3 (IRBIT) activation of NBCe1-B unmasks a second high affinity Cl-in(-) interacting GXXXP-dependent site. By contrast, NBCe2-C, which does not interact with IRBIT, has a single high affinity N-terminal GXXP-containing Cl-in(-) interacting site. NBCe1-A is unaffected by Cl-in(-) between 5 and 140 mM. However, deletion of NBCe1-A residues 29-41 unmasks a cryptic GXXXP-containing site homologous with the NBCe1-B low affinity site that is involved in inhibition of NBCe1-A by Cl-in(-). These findings reveal a cellular Cl-in(-) sensing mechanism that plays an important role in the regulation of Na+ and HCO3- transport, with critical implications for the role of Cl-in(-) cellular ion homeostasis and epithelial fluid and electrolyte secretion.</P>

Modulation of Cl⁻ signaling and ion transport by recruitment of kinases and phosphatases mediated by the regulatory protein IRBIT

Vachel, Laura,Shcheynikov, Nikolay,Yamazaki, Osamu,Fremder, Moran,Ohana, Ehud,Son, Aran,Shin, Dong Min,Yamazaki-Nakazawa, Ai,Yang, Chin-Rang,Knepper, Mark A.,Muallem, Shmuel AAAS 2018 Science signaling Vol.11 No.554

<P><B>Combinations to regulate Cl<SUP>−</SUP> signaling</B></P><P>The secretion of HCO<SUB>3</SUB><SUP>−</SUP>-containing fluids is vital to the function of all epithelia and is enabled in part by the activity of the Na<SUP>+</SUP>-coupled HCO<SUB>3</SUB><SUP>−</SUP> transporter NBCe1-B. Vachel <I>et al</I>. identified five serine residues in NBCe1-B whose phosphorylation status was controlled by the regulatory protein IRBIT. The phosphorylation status of Ser<SUP>12</SUP> and Ser<SUP>65</SUP> affected the Cl<SUP>−</SUP> sensitivity of two intracellular Cl<SUP>−</SUP>-sensing motifs. Moreover, IRBIT recruited a distinct kinase/phosphatase pair for each serine residue. The three remaining phosphorylation sites were phosphorylated in distinct combinations that determined the relative basal activity level of NBCe1-B and the potential for further activation by IRBIT. These results demonstrate how distinct phosphorylation patterns may enable epithelial cells to fine-tune the HCO<SUB>3</SUB><SUP>−</SUP> transport activity of NBCe1-B in response to varying conditions in different parts of the organ.</P><P>IRBIT is a multifunctional protein that controls the activity of various epithelial ion transporters including NBCe1-B. Interaction with IRBIT increases NBCe1-B activity and exposes two cryptic Cl<SUP>−</SUP>-sensing GXXXP sites that enable regulation of NBCe1-B by intracellular Cl<SUP>−</SUP> (Cl<SUP>−</SUP><SUB>in</SUB>). Here, phosphoproteomic analysis revealed that IRBIT controlled five phosphorylation sites in NBCe1-B that determined both the active conformation of the transporter and its regulation by Cl<SUP>−</SUP><SUB>in</SUB>. Mutational analysis suggested that the phosphorylation status of Ser<SUP>232</SUP>, Ser<SUP>233</SUP>, and Ser<SUP>235</SUP> was regulated by IRBIT and determined whether NBCe1 transporters are in active or inactive conformations. The absence of phosphorylation at Ser<SUP>232</SUP>, Ser<SUP>233</SUP>, or Ser<SUP>235</SUP> produced NBCe1-B in the conformations pSer<SUP>233</SUP>/pSer<SUP>235</SUP>, pSer<SUP>232</SUP>/pSer<SUP>235</SUP>, or pSer<SUP>232</SUP>/pSer<SUP>233</SUP>, respectively. The activity of the pSer<SUP>233</SUP>/pSer<SUP>235</SUP> form was similar to that of IRBIT-activated NBCe1-B, but it was insensitive to inhibition by Cl<SUP>−</SUP><SUB>in</SUB>. The properties of the pSer<SUP>232</SUP>/pSer<SUP>235</SUP> form were similar to those of wild-type NBCe1-B, whereas the pSer<SUP>232</SUP>/pSer<SUP>233</SUP> form was partially active, further activated by IRBIT, but retained inhibition by Cl<SUP>−</SUP><SUB>in</SUB>. Furthermore, IRBIT recruited the phosphatase PP1 and the kinase SPAK to control phosphorylation of Ser<SUP>65</SUP>, which affected Cl<SUP>−</SUP><SUB>in</SUB> sensing by the <SUP>32</SUP>GXXXP<SUP>36</SUP> motif. IRBIT also recruited the phosphatase calcineurin and the kinase CaMKII to control phosphorylation of Ser<SUP>12</SUP>, which affected Cl<SUP>−</SUP><SUB>in</SUB> sensing by the <SUP>194</SUP>GXXXP<SUP>198</SUP> motif. Ser<SUP>232</SUP>, Ser<SUP>233</SUP>, and Ser<SUP>235</SUP> are conserved in all NBCe1 variants and affect their activity. These findings reveal how multiple kinase and phosphatase pathways use phosphorylation sites to fine-tune a transporter, which have important implications for epithelial fluid and HCO<SUB>3</SUB><SUP>−</SUP> secretion.</P>

Effect of Vitamin D Status on Von Willebrand Factor and ADAMTS13 in Diabetic Patients on Chronic Hemodialysis

Keren Cohen-Hagai,Gloria Rashid,Yael Einbinder,Meital Ohana,Sydney Benchetrit,Tali Zitman-Gal 대한진단검사의학회 2017 Annals of Laboratory Medicine Vol.37 No.2

Von Willebrand factor (vWF) is a glycoprotein with a crucial role in the formation of platelet thrombi, and ADAMTS13 is the main enzyme responsible for vWF cleavage. Both are important in the relationship between diabetic nephropathy, hypercoagulability, and cardiovascular disease. This study evaluated a potential relationship between vitamin D (vitD) levels, vWF, ADAMTS13 activity, and inflammation in diabetic patients on chronic hemodialysis (HD). Blood samples from 52 diabetic patients on chronic HD were obtained to determine vitD levels, vWF, and ADAMTS13 activity, and inflammatory markers. HD patients were grouped according to 25-hydroxyvitamin D [25(OH) VitD]<25 nmol/L (n=16) or >25 nmol/L (n=36). vWF antigen and vWF activity were elevated in both groups, with an average of 214.3±82.6% and 175.8±72.6%, respectively. Average ADAMTS13 activity was within the normal range in both groups. Blood samples from the vitD <25 nmol/L group showed a positive correlation between c-reactive protein (CRP) and vWF levels (P=0.023; r=0.564; 95% confidence interval=0.095-0.828), with a negative correlation between HbA1c and 25(OH) VitD (P=0.015; r=-0.337; 95% confidence interval=-0.337-0.19). Diabetic patients on chronic HD had elevated vWF levels and activity with no significant change in ADAMTS13 activity. The correlation between CRP and vWF levels in the 25(OH) VitD<25 nmol/L group suggests inflammatory-related endothelial dysfunction in these patients.