scholarly journals Tilapia Prolactin Cells are Thermosensitive Osmoreceptors

2021 ◽  
Author(s):  
Daniel W. Woo ◽  
G.H.T. Malintha ◽  
Fritzie T. Celino-Brady ◽  
Yoko Yamaguchi ◽  
Jason P. Breves ◽  
...  
Keyword(s):  
Channel Blocker ◽  
Water Channel ◽  
Oreochromis Mossambicus ◽  
Mrna Levels ◽  
Pars Distalis ◽  
Prolactin Cells ◽  
A Cell ◽  
Euryhaline Teleost ◽  
Dependent Pathway ◽  
Rostral Pars Distalis

Abstract Prolactin (PRL) cells within the rostral pars distalis (RPD) of the euryhaline teleost tilapia, Oreochromis mossambicus, rapidly respond to a hyposmotic stimulus by releasing two distinct PRL isoforms, PRL188 and PRL177. Here, we describe how environmentally relevant temperatures affect the release and mRNA levels of PRL188 and PRL177 from RPDs and dispersed PRL cells. When applied under isosmotic conditions (330 mOsm/kg), a 6 °C rise in temperature stimulated the release of PRL188 and PRL177 from both RPDs and dispersed PRL cells under perifusion. When exposed to this same change in temperature, ~50% of dispersed PRL cells gradually increased in volume by ~8%, a response partially inhibited by the water channel blocker, HgCl2. Following their response to increased temperature, PRL cells remained responsive to a hyposmotic stimulus (280 mOsm/kg). The mRNA expression of transient potential vanilloid 4, a Ca2+-channel involved in hyposomotically-induced PRL release, was elevated in response to a rise in temperature in dispersed PRL cells and RPDs at 6 and 24 h, respectively; prl188 and prl177 mRNAs were unaffected. Our findings indicate that thermosensitive PRL release is mediated, at least partially, through a cell-volume dependent pathway similar to how osmoreceptive PRL release is achieved.

scholarly journals Prolactin 177, prolactin 188, and extracellular osmolality independently regulate the gene expression of ion transport effectors in gill of Mozambique tilapia

2015 ◽  
Vol 309 (10) ◽  
pp. R1251-R1263 ◽  
Author(s):  
Mayu Inokuchi ◽  
Jason P. Breves ◽  
Shunsuke Moriyama ◽  
Soichi Watanabe ◽  
Toyoji Kaneko ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mrna Expression ◽  
Incubation Time ◽  
Oreochromis Mossambicus ◽  
Mrna Levels ◽  
Ion Transporters ◽  
Local Effects ◽  
Mozambique Tilapia ◽  
Gill Filaments ◽  
Euryhaline Teleost

This study characterized the local effects of extracellular osmolality and prolactin (PRL) on branchial ionoregulatory function of a euryhaline teleost, Mozambique tilapia ( Oreochromis mossambicus). First, gill filaments were dissected from freshwater (FW)-acclimated tilapia and incubated in four different osmolalities, 280, 330, 380, and 450 mosmol/kg H2O. The mRNA expression of Na+/K+-ATPase α1a (NKA α1a) and Na+/Cl− cotransporter (NCC) showed higher expression with decreasing media osmolalities, while Na+/K+/2Cl− cotransporter 1a (NKCC1a) and PRL receptor 2 (PRLR2) mRNA levels were upregulated by increases in media osmolality. We then incubated gill filaments in media containing ovine PRL (oPRL) and native tilapia PRLs (tPRL177 and tPRL188). oPRL and the two native tPRLs showed concentration-dependent effects on NCC, NKAα1a, and PRLR1 expression; Na+/H+ exchanger 3 (NHE3) expression was increased by 24 h of incubation with tPRLs. Immunohistochemical observation showed that oPRL and both tPRLs maintained a high density of NCC- and NKA-immunoreactive ionocytes in cultured filaments. Furthermore, we found that tPRL177 and tPRL188 differentially induce expression of these ion transporters, according to incubation time. Together, these results provide evidence that ionocytes of Mozambique tilapia may function as osmoreceptors, as well as directly respond to PRL to modulate branchial ionoregulatory functions.

Activity of the pituitary gland in embryo and larval stages of coho salmon, Oncorhynchus kisutch

1975 ◽  
Vol 53 (3) ◽  
pp. 297-310 ◽  
Author(s):  
John F. Leatherland ◽  
L. Lin
Keyword(s):  
Coho Salmon ◽  
Cell Types ◽  
Well Water ◽  
Distilled Water ◽  
Endocrine Regulation ◽  
Pars Distalis ◽  
Prolactin Cells ◽  
Larval Stages ◽  
Hydromineral Regulation ◽  
Rostral Pars Distalis

Embryos of coho salmon appear to regulate their internal osmotic environment actively before hatching (Weisbart 1968). However, at the time of hatching the pituitary contains only small numbers of differentiated cell types and it is only within the 1st week after hatching that a rudimentary follicular rostral pars distalis containing active eta (prolactin) acidophils becomes apparent. This suggests that prolactin, which in adult salmonids appears to be involved in freshwater osmo(iono)regulation, may not be involved in the same way in the early larval stages.Late-stage coho alevins can withstand ambient salinities up to 65% seawater for a period of 3 to 4 days. Under these conditions the prolactin cells become less active than in similar fish acclimated to distilled water or well water. The data indicate that the endocrine regulation of freshwater osmo(iono)regulation in late alevins and early fry stages may be similar to that found in adults. The evidence for the involvement of other pituitary factors in the hydromineral regulation of coho fry in hypoosmotic or hyperosmotic environs is inconclusive.Morphological studies of the chorion of the egg and of the yolk sac of the embryo and alevin suggest that these organs are not actively involved in hydromineral regulation.

Osmosensitivity of prolactin cells is enhanced by the water channel aquaporin-3 in a euryhaline Mozambique tilapia (Oreochromis mossambicus)

2009 ◽  
Vol 296 (2) ◽  
pp. R446-R453 ◽  
Author(s):  
Soichi Watanabe ◽  
Tetsuya Hirano ◽  
E. Gordon Grau ◽  
Toyoji Kaneko
Keyword(s):  
Cell Volume ◽  
Significant Contribution ◽  
Water Channel ◽  
Inhibitory Effect ◽  
Prolactin Cells ◽  
Volume Increase ◽  
Aquaporin 3 ◽  
Mozambique Tilapia ◽  
Immunohistochemical Studies ◽  
Rostral Pars Distalis

In teleost fish, prolactin (PRL) has important actions in the regulation of salt and water balances in freshwater (FW) fish. Consistent with this role, the release of PRL from the pituitary of the Mozambique tilapia is stimulated as extracellular osmolality is reduced. Stretch-activated calcium-permeant ion channels appear to be responsible for the initiation of the signal transduction that leads to increased PRL release when PRL cells are exposed to reductions in extracellular osmolality. In this study, we examined a possible involvement of the aquaporin-3 (AQP3) water channel in this osmoreceptive mechanism in PRL cells of the tilapia. AQP3 expression levels in the rostral pars distalis of the pituitary, consisting predominantly of PRL cells, were higher in fish adapted to FW than in seawater (SW)-adapted fish. Immunohistochemical studies revealed that AQP3 is located in the cell membrane and perinuclear region of PRL cells, with more intense immunosignals in PRL cells of FW-adapted fish than in those of SW fish. In FW PRL cells, the magnitude of hyposmoticity-induced cell volume increase was greater than that seen in SW PRL cells. Mercury, a potent inhibitor of AQP3, inhibited hyposmoticity-induced cell volume increase and PRL release from FW PRL cells. The inhibitory effect of mercury was partially restored by β-mercaptoethanol, whereas no effect of mercury was observed on PRL release stimulated by a depolarizing concentration of KCl, which induces Ca2+ influx and stimulates the subsequent Ca2+-signaling pathway. These results indicate significant contribution of AQP3 to osmoreception in PRL cells in FW-adapted tilapia.

The loss of 45Ca2+ associated with prolactin release from the tilapia (Oreochromis mossambicus) rostral pars distalis

1991 ◽  
Vol 83 (1) ◽  
pp. 56-67 ◽  
Author(s):  
N. Harold Richman ◽  
Carol-Ann Ford ◽  
Lisa M.H. Helms ◽  
Ian M. Cooke ◽  
Peter K.T. Pang ◽  
...  
Keyword(s):  
Oreochromis Mossambicus ◽  
Pars Distalis ◽  
Prolactin Release ◽  
Rostral Pars Distalis

scholarly journals Is the primitive regulation of pituitary prolactin (tPRL177 and tPRL188) secretion and gene expression in the euryhaline tilapia (Oreochromis mossambicus) hypothalamic or environmental?

1999 ◽  
Vol 161 (1) ◽  
pp. 121-129 ◽  
Author(s):  
BS Shepherd ◽  
T Sakamoto ◽  
S Hyodo ◽  
RS Nishioka ◽  
C Ball ◽  
...  
Keyword(s):  
Gene Expression ◽  
Plasma Osmolality ◽  
Oreochromis Mossambicus ◽  
Mrna Levels ◽  
Prolactin Release ◽  
Plasma Factor ◽  
Operative Recovery ◽  
Pituitary Prolactin ◽  
Circulating Levels ◽  
Rostral Pars Distalis

We examined the effects of environmental salinity on circulating levels of the two prolactins (tPRL177 and tPRL188) and levels of pituitary tPRL177 and tPRL188 mRNA in the euryhaline tilapia, Oreochromis mossambicus. Fish were sham-operated or hypophysectomized and the rostral pars distalis (RPD) autotransplanted onto the optic nerve. Following post-operative recovery in (1/4) seawater, tilapia were transferred to fresh water (FW), (1/4) seawater (SW) or SW. Serum tPRL177 and tPRL188 levels in sham-operated and RPD-autotransplanted fish were highest in FW and decreased as salinity was increased. tPRL177 and tPRL188 mRNA levels in RPD implants as well as in pituitaries from the sham-operated fish were also highest in FW and decreased with increasing salinity. Serum osmolality increased with salinity, with the highest levels occurring in the seawater groups. We conclude that some plasma factor (probably plasma osmolality), in the absence of hypothalamic innervation, exerts a direct regulatory action on prolactin release and gene expression in the pituitary of O. mossambicus. This regulation is in accord with the actions of the two prolactins in the freshwater osmoregulation of the tilapia.

scholarly journals A cell-penetrating whole molecule antibody targeting intracellular HBx suppresses hepatitis B virus via TRIM21-dependent pathway

Theranostics ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 549-562 ◽  
Author(s):  
Jun-Fang Zhang ◽  
Hua-Long Xiong ◽  
Jia-Li Cao ◽  
Shao-Juan Wang ◽  
Xue-Ran Guo ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
B Virus ◽  
Cell Penetrating ◽  
A Cell ◽  
Antibody Targeting ◽  
Dependent Pathway

scholarly journals Stem cell factor and c-kit are involved in hepatic recovery after acetaminophen-induced liver injury in mice

2008 ◽  
Vol 295 (1) ◽  
pp. G45-G53 ◽  
Author(s):  
Bin Hu ◽  
Lisa M. Colletti
Keyword(s):  
Stem Cell ◽  
Liver Injury ◽  
Stem Cell Factor ◽  
Cellular Proliferation ◽  
Hepatocyte Proliferation ◽  
Mrna Levels ◽  
Wild Type ◽  
Hepatocyte Apoptosis ◽  
Large Reservoir ◽  
A Cell

Stem cell factor (SCF) and its receptor c-kit are important in hematopoiesis and cellular proliferation. c-kit has also been identified as a cell surface marker for progenitor cells. We have previously shown that there is a large reservoir of hepatic SCF, and this molecule plays a significant role in liver regeneration after 70% hepatectomy. In the current study, we further examined the expression of SCF and c-kit in acetaminophen (APAP)-induced liver injury in C57BL/6J mice or SCF-deficient sl-sld mice and their appropriate wild-type controls. Following APAP-induced liver injury, c-kit mRNA expression increased, with peak levels detected 48 h postinjury. Hepatic SCF mRNA levels after APAP injury were also increased, with peak levels seen 16 h post-APAP. The mortality rate in SCF-deficient mice treated with APAP was significantly higher than that of wild-type mice; furthermore, administration of exogenous SCF significantly reduced the mortality of APAP-treated wild-type mice. Bromodeoxyuridine incorporation experiments showed that SCF significantly increased hepatocyte proliferation at 48 and 72 h in APAP-treated mice. SCF inhibited APAP-induced hepatocyte apoptosis and increased Bcl-2 and Bcl-xL expression, suggesting that this decrease in hepatocyte apoptosis is mediated through Bcl-2 and Bcl-xL. In summary, SCF and c-kit expression was increased after APAP-induced liver injury. Administration of exogenous SCF reduces mortality in APAP-treated mice, increases hepatocyte proliferation, and prevents hepatocyte apoptosis induced by APAP, suggesting that these molecules are important in the liver's recovery from these injuries.

Control of proliferin gene expression in serum-stimulated mouse cells

1987 ◽  
Vol 7 (6) ◽  
pp. 2080-2086
Author(s):  
D I Linzer ◽  
E L Wilder
Keyword(s):  
Protein Synthesis ◽  
S Phase ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Serum Stimulation ◽  
Posttranscriptional Processing ◽  
A Cell ◽  
Mouse Cells ◽  
Stimulation Of

The serum-inducible expression of proliferin genes in BALB/c 3T3 cells was found to be dependent on both protein synthesis and an extended presence of serum in the medium. Even though no mature proliferin mRNA was detected in serum-starved cells, transcription of the proliferin genes occurred in these resting-cell cultures, indicating that posttranscriptional events may be important for regulating proliferin mRNA levels. These results suggest that protein synthesis after serum stimulation of quiescent mouse fibroblasts is required for posttranscriptional processing or stabilization of proliferin RNA. Proliferin RNA levels were found to be heterogeneous among serum-stimulated cells analyzed by in situ hybridization. This heterogeneity is probably due to asynchrony in the population and may point to a correlation between the time of proliferin expression and the time of entry of a cell into S phase.

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