scholarly journals in vivo cellular evidence of autophagic associated spermiophagy within the principal cells during sperm storage in epididymis of the turtle

Aging ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 8987-8999
Author(s):  
Imran Tarique ◽  
Yonghong Shi ◽  
Noor Samad Gandahi ◽  
Baitao Ding ◽  
Ping Yang ◽  
...  
Keyword(s):  
Sperm Storage ◽  
Principal Cells

Novel aspects of the transport of organic anions by the malpighian tubules of Drosophila melanogaster

2000 ◽  
Vol 203 (23) ◽  
pp. 3575-3584 ◽  
Author(s):  
S.M. Linton ◽  
M.J. O'Donnell
Keyword(s):  
Drosophila Melanogaster ◽  
Organic Acid ◽  
Organic Anion ◽  
Indigo Carmine ◽  
Organic Anions ◽  
Malpighian Tubules ◽  
Principal Cells ◽  
Anion Transporters ◽  
Mode Of Transport

Para-aminohippuric acid (PAH) is a negatively charged organic ion that can pass across the epithelium of Malpighian tubules. Its mode of transport was studied in Malpighian tubules of Drosophila melanogaster. PAH transport was an active process, with a K(m) of 2. 74 mmol l(−)(1) and a V(max) of 88.8 pmol min(−)(1). Tubules had a low passive permeability to PAH, but PAH transport rates (832 nmol min(−)(1)mm(2)) and concentrative ability ([PAH](secreted fluid):[PAH](bath)=81.2) were the highest measured to date for insects. Competition experiments indicated that there were two organic anion transporters, one that transports carboxylate compounds, such as PAH and fluorescein, and another that transports sulphonates, such as amaranth and Indigo Carmine. PAH transport appears to be maximal in vivo because the rate of transport by isolated tubules is not increased when these are challenged with cyclic AMP, cyclic GMP, leucokinin I or staurosporine. Basolateral PAH transport was inhibited by ouabain and dependent on the Na(+) gradient. The Malpighian tubules appeared not to possess an organic acid/ α -keto acid exchanger because PAH accumulation was not affected by low concentrations (100 μmol l(−)(1)) of α -keto acids (α -ketoglutarate, glutarate, citrate and succinate) or the activity of phosphokinase C. PAH transport may be directly coupled to the Na(+) gradient, perhaps via Na(+)/organic acid cotransport. Fluorescence microscopy showed that transport of the carboxylate fluorescein was confined to the principal cells of the main (secretory) segment and all the cells of the lower (reabsorptive) segment. Organic anions were transported across the cytoplasm of the principal cells both by diffusion and in vesicles. The accumulation of punctate fluorescence in the lumen is consistent with exocytosis of the cytoplasmic vesicles. Apical PAH transport was independent of the apical membrane potential and may not occur by an electrodiffusive mechanism.

The Effect of in Vivo Sperm Storage Interval to Fertility and Embryonic Survival in the Korean Indigenous Chicken in Winter Season

2015 ◽  
Vol 27 (3) ◽  
pp. 374-380
Author(s):  
Hyun Kim ◽  
Mi Jeong Byun ◽  
Young Moo Cho ◽  
Jae-Hwan Kim ◽  
Sung-Soo Lee ◽  
...  
Keyword(s):  
Winter Season ◽  
Sperm Storage ◽  
Indigenous Chicken ◽  
Embryonic Survival

Stimulation of AQP2 membrane insertion in renal epithelial cells in vitro and in vivo by the cGMP phosphodiesterase inhibitor sildenafil citrate (Viagra)

2005 ◽  
Vol 288 (6) ◽  
pp. F1103-F1112 ◽  
Author(s):  
Richard Bouley ◽  
Nuria Pastor-Soler ◽  
Ori Cohen ◽  
Margaret McLaughlin ◽  
Sylvie Breton ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Collecting Duct ◽  
Sildenafil Citrate ◽  
Membrane Insertion ◽  
Vasopressin Receptor ◽  
Pde5 Inhibitors ◽  
Principal Cells ◽  
Medullary Collecting Duct

Vasopressin-stimulated insertion of the aquaporin 2 (AQP2) water channel into the plasma membrane of kidney collecting duct principal cells is a key event in the urinary concentrating mechanism. The paradigm for vasopressin-receptor signaling involves cAMP-mediated protein kinase A activation, which results in the functionally critical phosphorylation of AQP2 on amino acid serine 256. We previously showed that a parallel cGMP-mediated signaling pathway also leads to AQP2 membrane insertion in AQP2-transfected LLC-PK1 (LLC-AQP2) cells and in outer medullary collecting duct principal cells in situ (Bouley R, Breton S, Sun T, McLaughlin M, Nsumu NN, Lin HY, Ausiello DA, and Brown D. J Clin Invest 106: 1115–1126, 2000). In the present report, we show by immunofluorescence microscopy, and Western blotting of plasma membrane fractions, that 45-min exposure of LLC-AQP2 cells to the cGMP phosphodiesterase type 5 (PDE5) inhibitors sildenafil citrate (Viagra) or 4-{[3',4'-methylene-dioxybenzyl]amino}-6-methoxyquinazoline elevates intracellular cGMP levels and results in the plasma membrane accumulation of AQP2; i.e., they mimic the vasopressin effect. Importantly, our data also show that acute exposure to PDE5 inhibitors for 60 min induces apical accumulation of AQP2 in kidney medullary collecting duct principal cells both in tissue slices incubated in vitro as well as in vivo after intravenous injection of Viagra into rats. These data suggest that AQP2 membrane insertion can be induced independently of vasopressin-receptor activation by activating a parallel cGMP-mediated signal transduction pathway with cGMP PDE inhibitors. These results provide proof-of-principle that pharmacological activation of vasopressin-independent, cGMP signaling pathways could aid in the treatment of those forms of nephrogenic diabetes insipidus that are due to vasopressin-2 receptor dysfunction.

Does apoptosis hold the key to long-term sperm storage mechanisms in vivo?

2011 ◽  
Vol 78 (7) ◽  
pp. 464-465 ◽  
Author(s):  
William V. Holt
Keyword(s):  
Sperm Storage

scholarly journals Role of cAMP/PKA signaling cascade in vasopressin-induced trafficking of TRPC3 channels in principal cells of the collecting duct

2010 ◽  
Vol 298 (4) ◽  
pp. F988-F996 ◽  
Author(s):  
Monu Goel ◽  
Cheng-Di Zuo ◽  
William P. Schilling
Keyword(s):  
Apical Membrane ◽  
Collecting Duct ◽  
Surface Membrane ◽  
Transient Receptor Potential Channels ◽  
Signaling Cascade ◽  
Dibutyryl Camp ◽  
Principal Cells ◽  
V2 Receptor ◽  
Stimulation Of

Transient receptor potential channels TRPC3 and TRPC6 are expressed in principal cells of the collecting duct (CD) along with the water channel aquaporin-2 (AQP2) both in vivo and in the cultured mouse CD cell line IMCD-3. The channels are primarily localized to intracellular vesicles, but upon stimulation with the antidiuretic hormone arginine vasopressin (AVP), TRPC3 and AQP2 translocate to the apical membrane. In the present study, the effect of various activators and inhibitors of the adenylyl cyclase (AC)/cAMP/PKA signaling cascade on channel trafficking was examined using immunohistochemical techniques and by biotinylation of surface membrane proteins. Both in vivo in rat kidney and in IMCD-3 cells, translocation of AQP2 and TRPC3 (but not TRPC6) was stimulated by [deamino-Cys1, d-Arg8]-vasopressin (dDAVP), a specific V2-receptor agonist, and blocked by [adamantaneacetyl1, O-Et-d-Tyr2, Val4, aminobutyryl6, Arg8,9]-vasopressin (AEAVP), a specific V2-receptor antagonist. In IMCD-3 cells, translocation of TRPC3 and AQP2 was activated by forskolin, a direct activator of AC, or by dibutyryl-cAMP, a membrane-permeable cAMP analog. AVP-, dDAVP-, and forskolin-induced translocation in IMCD-3 cells was blocked by SQ22536 and H89, specific inhibitors of AC and PKA, respectively. Translocation stimulated by dibutyryl-cAMP was unaffected by AEAVP but could be blocked by H89. AVP- and forskolin-induced translocation of TRPC3 in IMCD-3 cells was also blocked by two additional inhibitors of PKA, specifically Rp-cAMPS and the myristoylated inhibitor of PKA (m-PKI). Quantification of TRPC3 membrane insertion in IMCD-3 cells under each assay condition using a surface membrane biotinylation assay, confirmed the translocation results observed by immunofluorescence. Importantly, AVP-induced translocation of TRPC3 as estimated by biotinylation was blocked on average 95.2 ± 1.0% by H89, Rp-cAMPS, or m-PKI. Taken together, these results demonstrate that AVP stimulation of V2 receptors in principal cells of the CD causes translocation of TRPC3 to the apical membrane via stimulation of the AC/cAMP/PKA signaling cascade.

Structural and functional differences distinguish principal from nonprincipal cells in the guinea pig MSO slice

1995 ◽  
Vol 73 (4) ◽  
pp. 1653-1667 ◽  
Author(s):  
P. H. Smith
Keyword(s):  
Guinea Pig ◽  
Low Frequency ◽  
Cell Types ◽  
Principal Cell ◽  
Superior Olivary Complex ◽  
Axon Collateral ◽  
Medial Superior Olive ◽  
Principal Cells ◽  
Current Pulses

1. Principal cells in the medial superior olive (MSO) receive low-frequency information from both ears via left and right cochlear nuclei. In vivo extracellular records suggest that some MSO neurons respond optimally only when the binaural acoustic signal has a precise interaural delay. Thus MSO cells, in particular principal cells, are thought to be the first stage in the processing of interaural time difference cues that provides information as to the location of a low-frequency sound in space. 2. Despite this proposed fundamental role for the MSO, certain features of this nucleus make in vivo recordings from any cell type here very difficult to obtain. Only a small number of extracellular records and no intracellular recordings are reported in the literature. Using sharp, neurobiotin-filled glass electrodes to record intracellularly from cells in an in vitro brain slice of the guinea pig superior olivary complex, I have begun to assess the anatomic and physiological features of cells in the MSO that might be relevant to such a functional role in vivo. 3. Two basic MSO cell types, designated principal and nonprincipal, could be distinguished on the basis of certain anatomic and physiological differences. 4. Labeled principal cell bodies were located at all dorsoventral location within the MSO. Labeled nonprincipal cells were located in or around the dorsal aspects of the nucleus. Principal cells typically had thick bipolar dendrites (1 directed medially, 1 laterally) that did not taper or branch significantly except at their terminations. Nonprincipal cells were multipolar with three to nine thinner primary dendrites that did not branch preferentially in a mediolateral direction. Principal cell axons gave off collaterals terminating in and around the dorsal MSO. Nonprincipal cells also had axon in and around the dorsal MSO. Nonprincipal cells also had axon collateral branches innervating dorsal MSO, but these axons could branch more extensively and project further down the dorsoventral aspect of the nucleus. 5. Principal cells typically responded to depolarizing current pulses with one or a few spikes at current onset. When bathed in saline containing 4-aminopyridine (4-AP), they fired repetitively to the same depolarizing current pulses. This would indicate a depolarization-induced nonlinearity similar to that seen in principal cell types of two other auditory brain stem nuclei, the anteroventral cochlear nucleus and medial nucleus of the trapezoid body. Nonprincipal cells normally fired repetitively to depolarizing current pulses even close to spike threshold. Both cell types could show a sag in the membrane potential to hyperpolarizing current pulses.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Specific features of in vivo and in vitro sperm storage in birds

animal ◽  
2007 ◽  
Vol 1 (10) ◽  
pp. 1472-1481 ◽  
Author(s):  
E. Blesbois ◽  
J.P. Brillard
Keyword(s):  
Sperm Storage

scholarly journals Role of TRPC3 channels in ATP-induced Ca2+ signaling in principal cells of the inner medullary collecting duct

2010 ◽  
Vol 299 (1) ◽  
pp. F225-F233 ◽  
Author(s):  
Monu Goel ◽  
William P. Schilling
Keyword(s):  
Transient Receptor Potential ◽  
Apical Membrane ◽  
Collecting Duct ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Dominant Negative ◽  
Principal Cells ◽  
Basolateral Side ◽  
Influx Pathways

The transient receptor potential channel TRPC3 is exclusively expressed in the apical membrane of principal cells of the collecting duct (CD) both in vivo and in the mouse CD cell line IMCD-3. Previous studies revealed that ATP-induced apical-to-basolateral transepithelial Ca2+ flux across IMCD-3 monolayers is increased by overexpression of TRPC3 and attenuated by a dominant negative TRPC3 construct, suggesting that Ca2+ entry across the apical membrane occurs via TRPC3 channels. To test this hypothesis, we selectively measured the Ca2+ permeability of the apical membrane of fura-2-loaded IMCD-3 cells using the Mn2+ quench technique. Mn2+ influx across the apical membrane was increased 12- to 16-fold by apical ATP and was blocked by the pyrazole derivative BTP2, a known inhibitor of TRPC3 channels, with an IC50 value <100 nM. In contrast, Mn2+ influx was only increased ∼2-fold by basolateral ATP. Mn2+ influx was also activated by apical, but not basolateral, 1-stearoyl-2-acetyl- sn-glycerol (SAG), a known activator of TRPC3 channels. Apical ATP- and SAG-induced Mn2+ influx was increased by overexpression of TRPC3 and completely blocked by expression of the dominant negative TRPC3 construct. Mn2+ influx was also stimulated ∼2-fold by thapsigargin applied to either the apical or basolateral side. Thapsigargin-induced flux was blocked by BTP2 but was unaffected by overexpression of TRPC3 or by dominant negative TRPC3. Apical ATP, but not basolateral ATP, increased transepithelial 45Ca2+ flux. These results demonstrate that the apical membrane of IMCD-3 cells has two distinct Ca2+ influx pathways: 1) a store-operated channel activated by thapsigargin and basolateral ATP and 2) TRPC3 channels activated by apical ATP. Only activation of TRPC3 leads to net transepithelial apical-to-basolateral Ca2+ flux. Furthermore, these results demonstrate that native TRPC3 is not a store-operated channel in IMCD-3 cells.

scholarly journals High-throughput chemical screening identifies AG-490 as a stimulator of aquaporin 2 membrane expression and urine concentration

2014 ◽  
Vol 307 (7) ◽  
pp. C597-C605 ◽  
Author(s):  
Naohiro Nomura ◽  
Paula Nunes ◽  
Richard Bouley ◽  
Anil V. Nair ◽  
Stanley Shaw ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
High Throughput ◽  
Membrane Expression ◽  
Chemical Screening ◽  
Principal Cells ◽  
Kidney Slices ◽  
Aquaporin 2 ◽  
Urine Production

A reduction or loss of plasma membrane aquaporin 2 (AQP2) in kidney principal cells due to defective vasopressin (VP) signaling through the VP receptor causes excessive urine production, i.e., diabetes insipidus. The amount of AQP2 on the plasma membrane is regulated by a balance of exocytosis and endocytosis and is the rate limiting step for water reabsorption in the collecting duct. We describe here a systematic approach using high-throughput screening (HTS) followed by in vitro and in vivo assays to discover novel compounds that enhance vasopressin-independent AQP2 membrane expression. We performed initial chemical library screening with a high-throughput exocytosis fluorescence assay using LLC-PK1 cells expressing soluble secreted yellow fluorescent protein and AQP2. Thirty-six candidate exocytosis enhancers were identified. These compounds were then rescreened in AQP2-expressing cells to determine their ability to increase AQP2 membrane accumulation. Effective drugs were then applied to kidney slices in vitro. Three compounds, AG-490, β-lapachone, and HA14-1 increased AQP2 membrane accumulation in LLC-PK1 cells, and both AG-490 and β-lapachone were also effective in MDCK cells and principal cells in rat kidney slices. Finally, one compound, AG-490 (an EGF receptor and JAK-2 kinase inhibitor), decreased urine volume and increased urine osmolality significantly in the first 2–4 h after a single injection into VP-deficient Brattleboro rats. In conclusion, we have developed a systematic procedure for identifying new compounds that modulate AQP2 trafficking using initial HTS followed by in vitro assays in cells and kidney slices, and concluding with in vivo testing in an animal model.

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