Expression of the rhesus glycoproteins, ammonia transporter family members, RHCG and RHBG in male reproductive organs

Lee, Hyun-Wook,Verlander, Jill W,Handlogten, Mary E,Han, Ki-Hwan,Cooke, Paul S,Weiner, I David BioScientifica Ltd 2013 Reproduction Vol.146 No.3

<P>The rhesus glycoproteins, Rh B glycoprotein (RHBG) and Rh C glycoprotein (RHCG), are recently identified ammonia transporters. Rhcg expression is necessary for normal male fertility, but its specific cellular expression is unknown, and Rhbg has not been reported to be expressed in the male reproductive tract. This study sought to determine the specific cellular expression of Rhcg, to determine whether Rhbg is expressed in the male reproductive tract, and, if so, to determine which cells express Rhbg using real-time RT-PCR, immunoblot analysis, and immunohistochemistry. Both Rhbg and Rhcg were expressed throughout the male reproductive tract. In the testis, high levels of Rhbg were expressed in Leydig cells, and Rhcg was expressed in spermatids during the later stages of their maturation (steps 13–16) in stages I–VIII of the seminiferous epithelium cycle. In the epididymis, basolateral Rhbg was present in narrow cells in the initial segment, in principal cells in the upper corpus, and in clear cells throughout the epididymis. Apical Rhcg immunolabel was present in principal cells in the caput and upper corpus epididymidis and in clear cells in the middle and lower corpus and cauda epididymidis. In the vas deferens, apical Rhcg immunolabel and basolateral Rhbg immunolabel were present in some principal cells and colocalized with H<SUP>+</SUP>-ATPase immunolabel. We conclude that both Rhbg and Rhcg are highly expressed in specific cells in the male reproductive tract where they can contribute to multiple components of male fertility.</P>

Expression of the Ammonium Transporter Proteins RhBG and RhCG in Developing Rat Kidney

( Ki Hwan Han ),( Kirsten M. Madsen ),( I. David Weiner ),( Jin Kim ) 대한신장학회 2004 춘계학술대회 초록집 Vol.24 No.1

Expression of Rh Glycoproteins in the Mammalian Kidney

( Ki Hwan Han ),( Hye Young Kim ),( I. David Weiner ) 대한전해질학회 2009 Electrolytes & Blood Pressure Vol.7 No.1

Ammonia metabolism is a fundamental process in the maintenance of life in all living organisms. Recent studies have identified ammonia transporter family proteins in yeast (Mep), plants (Amt), and mammals (Rh glycoproteins). In mammalian kidneys, where ammonia metabolism and transport are critically important for the regulation of systemic acid-base homeostasis, basolateral Rh B glycoprotein and apical/basolateral Rh C glycoprotein are expressed along the distal nephron segments. Data from experimental animal models and knockout mice suggest that the Rh glycoproteins appear to mediate important roles in urinary ammonia excretion.

Fluid Electrolyte & Acid Base Disorder : Localization of the Ammonia Transporter, Rhcg, in Intercalated Cell Subtypes of Human Kidney

( Ki Hwan Han ),( Jin Kim ),( Byron P. Croker ),( I. David Weiner ) 대한신장학회 2006 춘계학술대회 초록집 Vol.25 No.1

Renal ischemia–reperfusion injury causes intercalated cell-specific disruption of occludin in the collecting duct

Lee, Su-Youn,Shin, Jung-A,Kwon, H. Moo,Weiner, I. David,Han, Ki-Hwan Springer-Verlag 2011 Histochemistry and cell biology Vol.136 No.6

<P>Renal ischemic events open tight junctions and disrupt epithelial polarity. The purpose of this study was to examine the effects of ischemia–reperfusion (IR) injury on expression and distribution of the tight junction proteins, occludin and ZO-1, in the rat kidney. IR injury was induced by clamping both renal pedicles for 30 min and animals were killed at 6 h after the reperfusion. IR injury decreased blood bicarbonate level, but did not persistently alter pH, Na<SUP>+</SUP>, K<SUP>+</SUP>, or Cl<SUP>−</SUP>. In control kidneys, occludin immunoreactivity was intense in the tight junctions in the thick ascending limb, distal convoluted tubule, and collecting duct, moderate in the thin limbs of the loop of Henle, and was not detected in the proximal tubule, glomerulus, and blood vessels. ZO-1 was expressed in the same sites in which occludin was expressed, and additionally was also expressed in the proximal tubule, glomerulus, and vascular endothelial cells. IR kidneys exhibited damaged renal tubular epithelial cells in both proximal tubule and collecting duct segments in the outer medulla. In the collecting duct, the response of intercalated cells and principal cells differed. Following IR injury, intercalated cells, but not principal cells, lost their normal epithelial polarity and were frequently extruded into the tubule lumen. Occludin, instead of being localized to tight junctions, was localized diffusely in the cytoplasm in intercalated cells of IR kidneys. Principal cells, in contrast, were not detectably affected and neither occludin nor ZO-1 expression were altered in response to IR injury. The normal localization of ZO-1 expression to tight junction sites in both the proximal tubule and collecting duct was altered in response to IR, and, instead, ZO-1 expression was present diffusely in the cytoplasm. IR injury did not alter detectably either occludin or ZO-1 localization to the tight junction of the thick ascending limb cells. The abundance of total occludin protein by immunoblot analysis was not changed with IR injury. These results demonstrate that renal IR injury causes tight junction disruptions in both the proximal tubule and the collecting duct, and that altered distribution of the tight junction protein, occludin, may play a critical role in the collecting duct dysfunction which IR induces.</P>

일반연제 발표 : 만성 사이클로스포린 신증에서 암모니아 수송체(RhBG, RhCG)의 발현

양철우,안경옥,임선우,기정연,양현주,김완영,한기환,김진,( I. David Weiner ) 대한신장학회 2006 춘계학술대회 초록집 Vol.25 No.1

흰쥐의 집합관 사이세포에서 암모니아 운반체 RhBG의 세포내 미세구조적 위치

한기환(Ki-Hwan Han),김완영(Wan-Young Kim),Jill W. Verlander, I. David Weiner, 김 진(Jin Kim) 대한해부학회 2005 Anatomy & Cell Biology Vol.38 No.2

콩팥의 집합관에서 일어나는 암모니아 배설은 산-염기평형의 조절에 중요한 역할을 한다. RhBG (Rh B Glycoprotein)는 최근에 밝혀진 새로운 암모니아 운반체(ammonium transporter)로 콩팥의 집합관에 존재하는 것으로 알려져 있다. 이 연구의 목적은 집합관 사이세포(intercalated cell)에서 RhBG의 미세구조적 위치를 관찰하는 것이다. Sprague-Dawley계의 흰쥐를 대상으로 광학 및 전자현미경적 면역세포화학법을 시행하였다. RhBG 면역반응성은 콩팥의 겉질, 바깥수질 및 속수질 시작부분 집합관의 일부 세포에서 관찰되었다. RhBG 면역반응성은 세포막자유면에 H±-ATPase를 발현하는 사이세포에서 강하게 나타났으나, pendrin을 발현하는 B형 세포와 주세포에서는 아주 약하거나 관찰되지 않았다. 전자현미경으로 관찰한 결과 RhBG는 주로 미세주름(microplicae)이 발달한 A형 사이세포의 바닥가쪽면 세포막(basolateral plasma membrane) 및 세포막주름 (infolding)에 위치하였으며, 미세융모(microvilli)를 가지고 있는 B형 사이세포에서는 아주 약하게 나타나는 것을 확인하였다. 이상의 결과로 암모니아 운반체 RhBG는 집합관에서 주로 산을 분비하는 A형 사이세포의 바닥가쪽면 세포막에 위치하여 산-염기평형과 관련된 암모니아 배설을 조절할 것으로 생각된다. Ammonia excretion in the renal collecting duct is critical in the regulation of the acid-base homeostasis. A novel family of ammonium transporter protein, Rh B Glycoprotein (RhBG) was recently identified in the mouse and rat kidney collecting duct. The purpose of this was to examine the ultrastructural localization of RhBG in the collecting duct. Rat kidneys were processed for light and electron microscope immunocytochemistry using anti- RhBG rabbit polyclonal antibody. Strong RhBG immunolabeling was observed in the basolateral plasma membrane of type A intercalated cells in the collecting duct. In contrast, RhBG labeling was very weak or negative in type B intercalated cells and rincipal cells. Transmission electron microscopy confirmed that RhBG immunostaining was located mainly in the basolateral plasma membrane and infoldings of type A intercalated cells, but very weak in type B cells. RhBG labeling was not observed in the apical plasma membrane both in type A and B cells. These results demonstrate that RhBG is a basolateral transporter in acid-secreting type A cells and may mediate ammonia excretion in the collecting duct.

Localization of the ammonia transporter, Rhcg, in normal and neoplastic human kidney

Ki-Hwan Han,Jin Kim,Byron P. Croker,I. David Weiner 대한체질인류학회 2006 대한체질인류학회 학술대회 연제 초록 Vol.49 No.-

Hydration status affects osteopontin expression in the rat kidney

Su-Youn Lee,Sae-Jin Lee,박홍림,Suk-Young Yang,I. David Weiner,김진,한기환 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.3

Osteopontin (OPN) is a secretory protein that plays an important role in urinary stone formation. Hydration status is associated with the development of urolithiasis. This study was conducted to examine the effects of dehydration and hydration on OPN expression in the rat kidney. Animals were divided into three groups, control, dehydrated, and hydrated. Kidney tissues were processed for light and electron microscope immunocytochemistry, in situ hybridization, and immunoblot analysis. Dehydration induced a significant increase in OPN protein expression, whereas increased fluid intake induced a decrease in protein expression. Under control conditions, OPN protein and mRNA expression were only detected in the descending thin limb (DTL). Dehydration induced increased expression in the DTL and the development of detectable expression in the thick ascending limb (TAL). In contrast, OPN expression levels declined to less than the controls in the DTL after hydration, while no expression of either protein or mRNA was detectable in the TAL. Immunoelectron microscopy demonstrated that hydration status altered tubular ultrastructure and intracellular OPN expression in the Golgi apparatus and secretory cytoplasmic vesicles. These data confirm that changes in oral fluid intake can regulate renal tubular epithelial cell OPN expression.

Effect of reduced renal mass on renal ammonia transporter family, Rh C glycoprotein and Rh B glycoprotein, expression.

Kim, Hye-Young,Baylis, Chris,Verlander, Jill W,Han, Ki-Hwan,Reungjui, Sirirat,Handlogten, Mary E,Weiner, I David American Physiological Society 2007 American Journal of Physiology Vol.293 No.4

<P>Kidneys can maintain acid-base homeostasis, despite reduced renal mass, through adaptive changes in net acid excretion, of which ammonia excretion is the predominant component. The present study examines whether these adaptations are associated with changes in the ammonia transporter family members, Rh B glycoprotein (Rhbg) and Rh C glycoprotein (Rhcg). We used normal Sprague-Dawley rats and a 5/6 ablation-infarction model of reduced renal mass; control rats underwent sham operation. After 1 wk, glomerular filtration rate, assessed as creatinine clearance, was decreased, serum bicarbonate was slightly increased, and Na(+) and K(+) were unchanged. Total urinary ammonia excretion was unchanged, but urinary ammonia adjusted for creatinine clearance, an index of per nephron ammonia metabolism, increased significantly. Although reduced renal mass did not alter total Rhcg protein expression, both light microscopy and immunohistochemistry with quantitative morphometric analysis demonstrated hypertrophy of both intercalated cells and principal cells in the cortical and outer medullary collecting duct that was associated with increased apical and basolateral Rhcg polarization. Rhbg expression, analyzed using immunoblot analysis, immunohistochemistry, and measurement of cell-specific expression, was unchanged. We conclude that altered subcellular localization of Rhcg contributes to adaptive changes in single-nephron ammonia metabolism and maintenance of acid-base homeostasis in response to reduced renal mass.</P>