Estradiol upregulates the expression of oxytocin receptor in colon in rats

2009 ◽  
Vol 296 (5) ◽  
pp. E1059-E1066 ◽  
Author(s):  
Mei Feng ◽  
Junfang Qin ◽  
Chao Wang ◽  
Yanfang Ye ◽  
Shuanglian Wang ◽  
...  
Keyword(s):  
Myenteric Plexus ◽  
Distal Colon ◽  
Colon Motility ◽  
Rt Pcr ◽  
Excitatory Effect ◽  
Ovx Rats ◽  
Voltage Dependent ◽  
Female Wistar Rats

The study was designed to investigate the effect of estradiol on the excitatory effect of oxytocin (OT) on colon motility. Female Wistar rats were used, and some of them were ovariectomized (OVX) and treated with vehicle or estradiol (E2). A plastic balloon made of condom was inserted into colon to monitor the change of colonic pressure in vivo. Longitudinal muscle strips of distal colon were prepared to monitor the spontaneous contraction of colon in vitro. Expression of OT receptor (OTR) was investigated by Western blot analysis. Expression of OTR mRNA was detected by RT-PCR. Immunohistochemistry was used to locate OTR. In OVX rats, pretreatment of E2 (4–100 μg/kg sc) dose-dependently increased the excitatory effect of OT on colon motility both in vivo and in vitro and increased the expression of OTR and OTR mRNA in colon. Systemic administration of OT excited the colon motility in vivo in rats at perioda of proestrus and estrus but did not influence it at diestrus period, when the concentration of plasma E2 was lowest in the estrous cycle. Pretreatment of atosiban, the specific OTR antagonist, and TTX, the blocker of voltage-dependent sodium channel on nerve fiber, attenuated the excitatory effect of OT on colon motility. OTR was located in myenteric plexus of colon. These results suggested that E2 increased the excitatory effect of OT on colon motility by upregulating the expression of OTR in myenteric plexus.

The depressing (negative) effect of oestradiol benzoate on the in vitro secretion of LH and FSH by the pituitary gland of the LRH-pretreated long-term ovariectomized rat changes into the augmentative (positive) effect after discontinuation of the LRH-pretreatment

1985 ◽  
Vol 110 (3) ◽  
pp. 329-337 ◽  
Author(s):  
G. A. Schuiling ◽  
H. Moes ◽  
T. R. Koiter
Keyword(s):  
Depressing Effect ◽  
Ovx Rats ◽  
Gonadotrophin Secretion ◽  
Oestradiol Benzoate ◽  
Negative Effect ◽  
Positive Effect ◽  
Perifusion System

Abstract. The effect of pretreatment in vivo with oestradiol benzoate on in vitro secretion of LH and FSH was studied in long-term ovariectomized (OVX) rats both at the end of a 5-day continuous in vivo pretreatment with LRH and 4-days after cessation of such LRH pretreatment. Rats were on day 0 sc implanted with osmotic minipumps which released LRH at the rate of 250 ng/h. Control rats were implanted with a piece of silicone elastomer with the dimensions of a minipump. On days 2 and 4 the rats were injected with either 3 μg EB or with oil. On day 5 part of the rats were decapitated and the in vitro autonomous (i.e. non-LRH-stimulated) and 'supra-maximally' LRHstimulated release of LH and FSH was studied using a perifusion system. From other rats the minipumps were removed on day 5 and perifusion was performed on day 9. On the 5th day of the in vivo LRH pretreatment the pituitary LH/FSH stores were partially depleted; the pituitaries of the EB-treated rats more so than those of the oil-injected rats. EB alone had no significant effect on the content of the pituitary LH- and FSH stores. On day 9, i.e. 4 days after removal of the minipumps, the pituitary LH and FSH contents had increased in both the oil- and the EB injected rats, but had not yet recovered to control values. In rats not subjected to the 5-days pretreatment with LRH EB had a positive effect on the supra-maximally LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. EB had no effect on the non-stimulated secretion of FSH. After 5 days of in vivo pretreatment with LRH only, the in vitro non-stimulated and supra-maximally LRH-stimulated secretion of both LH and FSH were strongly impaired, the effect correlating well with the LRH-induced depletion of the pituitary LH/FSH stores. In such LRH-pretreated rats EB had on day 5 a negative effect on the (already depressed) LRH-stimulated secretion of LH (not on that of FSH). EB had no effect on the non-stimulated LH/FSH secretion. It could be demonstrated that the negative effect of the combined LRH/EB pretreatment was mainly due to the depressing effect of this treatment on the pituitary LH and FSH stores: the effect of oestradiol on the pituitary LRH-responsiveness (release as related to pituitary gonadotrophin content) remained positive. In LRH-pretreated rats, however, this positive effect of EB was smaller than in rats not pretreated with LRH. Four days after removal of the minipumps there was again a positive effect of EB on the LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. The positive effect of EB on the pituitary LRH-responsiveness was as strong as in rats which had not been exposed to exogenous LRH. The non-stimulated secretion of FSH was again not affected by EB. The results demonstrate that the effect of EB on the oestrogen-sensitive components of gonadotrophin secretion consists of two components: an effect on the pituitary LRH-responsiveness proper, and an effect on the pituitary LH/FSH stores. The magnitude of the effect of EB on the LRH-responsiveness is LRH dependent: it is very weak (almost zero) in LRH-pretreated rats, but strong in rats not exposed to LRH as well as in rats of which the LRH-pretreatment was stopped 4 days previously. Similarly, the effect of EB on the pituitary LH and FSH stores is LRH-dependent: in the absence of LRH, EB has no influence on the contents of these stores, but EB can potentiate the depleting effect of LRH on the LH/FSH-stores. Also this effect disappear after cessation of the LRH-pretreatment.

Inhibition of dihydropyridine-sensitive calcium entry in hypoxic relaxation of airway smooth muscle

1995 ◽  
Vol 268 (2) ◽  
pp. L201-L206 ◽  
Author(s):  
C. Vannier ◽  
T. L. Croxton ◽  
L. S. Farley ◽  
C. A. Hirshman
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Muscle Tone ◽  
Bay K 8644 ◽  
O2 Concentration ◽  
Voltage Dependent ◽  
Progressive Hypoxia ◽  
Carbamyl Choline

Hypoxia dilates airways in vivo and reduces active tension of airway smooth muscle in vitro. To determine whether hypoxia impairs Ca2+ entry through voltage-dependent channels (VDC), we tested the ability of dihydropyridines to modulate hypoxia-induced relaxation of KCl- and carbamyl choline (carbachol)-contracted porcine bronchi. Carbachol- or KCl-contracted bronchial rings were exposed to progressive hypoxia in the presence or absence of 1 microM BAY K 8644 (an L-type-channel agonist). In separate experiments, rings were contracted with carbachol or KCl, treated with nifedipine (a VDC antagonist), and finally exposed to hypoxia. BAY K 8644 prevented hypoxia-induced relaxation in KCl-contracted bronchi. Nifedipine (10(-5) M) totally relaxed KCl- contracted bronchi. Carbachol-contracted bronchi were only partially relaxed by nifedipine but were completely relaxed when the O2 concentration of the gas was reduced from 95 to 0%. These data indicate that hypoxia can reduce airway smooth muscle tone by limiting entry of Ca2+ through a dihydropyridine-sensitive pathway, but that other mechanisms also contribute to hypoxia-induced relaxation of carbachol-contracted bronchi.

Comparative Evaluation of In Vitro and In Vivo Assays for the Detection of Avian Infectious Bronchitis Virus as a Contaminant of Live Poultry Vaccines

1998 ◽  
Vol 26 (5) ◽  
pp. 629-634
Author(s):  
Emiliana Falcone ◽  
Edoardo Vignolo ◽  
Livia Di Trani ◽  
Simona Puzelli ◽  
Maria Tollis
Keyword(s):  
Infectious Bronchitis Virus ◽  
Serological Response ◽  
Avian Infectious Bronchitis Virus ◽  
Animal Testing ◽  
Rt Pcr ◽  
Pcr Assay ◽  
In Vivo Test ◽  
Infectious Bronchitis

A reverse transcriptase polymerase chain reaction (RT-PCR) assay specific for identifying avian infectious bronchitis virus (IBV) in poultry vaccines, and the serological response to IBV induced by the inoculation of chicks with a Newcastle disease vaccine spiked with the Massachusetts strain of IBV, were compared for their ability to detect IBV as a contaminant of avian vaccines. The sensitivity of the IBV-RT-PCR assay provided results which were at least equivalent to the biological effect produced by the inoculation of chicks, allowing this assay to be considered a valid alternative to animal testing in the quality control of avian immunologicals. This procedure can easily be adapted to detect a number of contaminants for which the in vivo test still represents the only available method of detection.

scholarly journals Interaction of periodontitis and orthodontic tooth movement—an in vitro and in vivo study

2021 ◽  
Author(s):  
Birgit Rath-Deschner ◽  
Andressa V. B. Nogueira ◽  
Svenja Beisel-Memmert ◽  
Marjan Nokhbehsaim ◽  
Sigrun Eick ◽  
...  
Keyword(s):  
Alveolar Bone ◽  
Tooth Movement ◽  
Mechanical Strain ◽  
Orthodontic Tooth Movement ◽  
Fusobacterium Nucleatum ◽  
In Vivo Study ◽  
Rt Pcr ◽  
Periodontal Inflammation

Abstract Objectives The aim of this in vitro and in vivo study was to investigate the interaction of periodontitis and orthodontic tooth movement on interleukin (IL)-6 and C-X-C motif chemokine 2 (CXCL2). Materials and methods The effect of periodontitis and/or orthodontic tooth movement (OTM) on alveolar bone and gingival IL-6 and CXCL2 expressions was studied in rats by histology and RT-PCR, respectively. The animals were assigned to four groups (control, periodontitis, OTM, and combination of periodontitis and OTM). The IL-6 and CXCL2 levels were also studied in human gingival biopsies from periodontally healthy and periodontitis subjects by RT-PCR and immunohistochemistry. Additionally, the synthesis of IL-6 and CXCL2 in response to the periodontopathogen Fusobacterium nucleatum and/or mechanical strain was studied in periodontal fibroblasts by RT-PCR and ELISA. Results Periodontitis caused an increase in gingival levels of IL-6 and CXCL2 in the animal model. Moreover, orthodontic tooth movement further enhanced the bacteria-induced periodontal destruction and gingival IL-6 gene expression. Elevated IL-6 and CXCL2 gingival levels were also found in human periodontitis. Furthermore, mechanical strain increased the stimulatory effect of F. nucleatum on IL-6 protein in vitro. Conclusions Our study suggests that orthodontic tooth movement can enhance bacteria-induced periodontal inflammation and thus destruction and that IL-6 may play a pivotal role in this process. Clinical relevance Orthodontic tooth movement should only be performed after periodontal therapy. In case of periodontitis relapse, orthodontic therapy should be suspended until the periodontal inflammation has been successfully treated and thus the periodontal disease is controlled again.

scholarly journals miR-142-3p Suppresses Cell Growth by Targeting CDK4 in Colorectal Cancer

2018 ◽  
Vol 51 (4) ◽  
pp. 1969-1981 ◽  
Author(s):  
Xiangyu Zhu ◽  
Si-ping Ma ◽  
Dongxiang Yang ◽  
Yanlong Liu ◽  
Yong-peng Wang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Growth ◽  
Tumor Cell ◽  
Nude Mice ◽  
Colony Formation ◽  
Tumor Cell Growth ◽  
Rt Pcr ◽  
Tumor Tissues

Background/Aims: Deregulation of microRNAs (miRNAs) has been associated with a variety of cancers, including colorectal cancer (CRC). Here, we investigated anomalous miR-142-3p expression and its possible functional consequences in primary CRC samples. Methods: The expression of miR-142-3p was measured by quantitative RT-PCR in 116 primary CRC tissues and adjacent non-tumor tissues. The effect of miR-142-3p up- or down-regulation in CRC-derived cells was evaluated in vitro by cell viability and colony formation assays and in vivo by growth assays in xenografted nude mice. Results: Using quantitative RT-PCR, we found that miR-142-3p was down-regulated in 78.4 % (91/116) of the primary CRC tissues tested when compared to the adjacent non-tumor tissues. We also found that the miR-142-3p mimic reduced in vitro cell viability and colony formation by inducing cell cycle arrest in CRC-derived cells, and inhibited in vivo tumor cell growth in xenografted nude mice. Inversely, we found that the miR-142-3p inhibitor increased the viability and colony forming capacity of CRC-derived cells and tumor cell growth in xenografted nude mice. In addition, we identified CDK4 as a potential target of miR-142-3p by predictions and dual-luciferase reporter assays. Concordantly, we found that miR-142-3p mimics and inhibitors could decrease and increase CDK4 protein levels in CRC-derived cells, respectively. Conclusion: From our results we conclude that miR-142-3p may act as a tumor suppressor in CRC and may serve as a tool for miRNA-based CRC therapy.

Mechanisms of neocortical epileptogenesis in vitro

1982 ◽  
Vol 48 (6) ◽  
pp. 1321-1335 ◽  
Author(s):  
M. J. Gutnick ◽  
B. W. Connors ◽  
D. A. Prince
Keyword(s):  
Reversal Potential ◽  
Excitatory Input ◽  
Short Latency ◽  
Resting Potential ◽  
Excitatory Postsynaptic Potential ◽  
Cellular Mechanisms ◽  
Voltage Dependent ◽  
Intact Cortex

1. The cellular mechanisms underlying interictal epileptogenesis have been examined in an in vitro slice preparation of guinea pig neocortex. Penicillin or bicuculline was applied to the tissue, and intracellular recordings were obtained from neurons and glia. 2. Following convulsant application, stimulation could elicit a short-latency excitatory postsynaptic potential (EPSP) and a large, longer latency depolarization shift (DS) in single neurons. DSs in neurons of the slice were very similar to those evoked in neurons of neocortex in vivo in that they displayed an all-or-none character, large shifts in latency during repetitive stimuli, long afterpotentials, and a prolonged refractory period. In contrast to epileptogenesis produced by penicillin in intact cortex, neither spontaneous DSs nor ictal episodes were observed in neocortical slices. 3. In simultaneous recordings from pairs of neurons within the same cortical column, DS generation and latency shifts were invariably synchronous. DS generation in neurons was also coincident with large, paroxysmal increases of extracellular [K+], as indicated by simultaneous recordings from glia. 4. When polarizing currents were applied to neurons injected with the local anesthetic QX-314, the DS amplitude varied monotonically and had an extrapolated reversal potential near 0 mV. In neurons injected with the K+-current blocker Cs+, large displacements of membrane potential were possible, and both the short-latency EPSP and the peak of the DS diminished completely at about 0 mV. At potentials positive to this, the short-latency EPSP was reversed, and the DS was replaced by a paroxysmal hyperpolarization whose rise time and peak latency were prolonged compared to the DS evoked at resting potential. The paroxysmal hyperpolarization probably represents the prolonged activation of the impaled neuron by EPSPs. 5. Voltage-dependent components, including slow spikes, appeared to contribute to generation of the DS at resting potential in Cs+-filled cells, and these components were blocked during large depolarizations. 6. The results suggest that DS generation in single neocortical neurons occurs during synchronous synaptic activation of a large group of cells. DS onset in a given neuron is determined by the timing of a variable-latency excitatory input that differs from the short-latency EPSP. The DS slow envelope appears to be generated by long-duration excitatory synaptic currents and may be modulated by intrinsic voltage-dependent membrane conductances. 7. We present a hypothesis for the initiation of the DS, based on the anatomical and physiological organization of the intrinsic neocortical circuits.

scholarly journals CircRNA PIP5K1A promotes the progression of glioma through upregulation of TCF12/PI3K/AKT pathway by sponging miR-515-5p

2020 ◽  
Author(s):  
Kebin Zheng ◽  
Haipeng Xie ◽  
Xiaosong Wu ◽  
Xichao Wen ◽  
Zhaomu Zeng ◽  
...  
Keyword(s):  
Epithelial Mesenchymal Transition ◽  
Cell Model ◽  
Luciferase Reporter ◽  
Akt Pathway ◽  
Circular Rnas ◽  
Rt Pcr ◽  
Mesenchymal Transition ◽  
Normal Tissues

Abstract BackgroundIncreasing studies have revealed that circular RNAs (CircRNAs) make great contribution to regulating tumor progression. Therefore, we intended to explore the expression characteristics, function, and related mechanisms of a novel type of circRNA, PIP5K1A in glioma. MethodsFirstly, RT-PCR was carried out to examine CircPIP5K1A expression in glioma tissues and adjacent normal tissues, and the correlation between CircPIP5K1A level and the clinical pathological indicators of glioma was analyzed. Then, the CircPIP5K1A expression in various glioma cell lines was detected, and a cell model of CircPIP5K1A overexpression and knockdown was constructed. Subsequently, cell proliferation and viability were detected by CCK8 method and BrdU staining, apoptosis was detected by flow cytometry, and cell invasion was examined by Transwell assay. The expression of TCF12, PI3K/AKT pathway apoptotic related proteins (including Caspase3, Bax and Bcl2) and epithelial-mesenchymal transition (EMT) markers (including E-cadherin, Vimentin and N-cadherin) by western blot or RT-PCR. ResultsThe results manifested that CircPIP5K1A was obviously upregulated in glioma tissues (compared with that in normal adjacent tissues), and overexpressed CircPIP5K1A was distinctly related to glioma volume and histopathological grade. Functionally, overexpressing CircPIP5K1A notably elevated the proliferation, invasion, EMT of glioma cells, and inhibited apoptosis both in vivo and in vitro. Besides, CircPIP5K1A also upregulated TCF12 and PI3K/AKT pathway activation. Bioinformatics analysis testified that miR-515-5p was a common target of CircPIP5K1A and TCF12, while dual luciferase reporter assay and RNA immunocoprecipitation (RIP) experiment further confirmed that CircPIP5K1A targeted miR-515-5p, which bound the 3'-untranslated region (UTR) of TCF12. ConclusionsAltogether, the study illustrated that CircPIP5K1A is a potential prognostic marker in glioma and regulates the development of glioma through the modulating miR-515-5p mediated TCF12/PI3K/AKT axis.

Δημιουργία, in vitro πολλαπλασιασμός και διαφοροποίηση ανθρώπινων επαγόμενων πολυδύναμων βλαστοκυττάρων

2016 ◽  
Author(s):  
Ιωάννα Βαρελά
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Pluripotent Stem Cells ◽  
Rt Pcr ◽  
Induced Pluripotent

Η ανακάλυψη της μεθόδου του κυτταρικού επαναπρογραμματισμού ανθρώπινων δερματικών ινοβλαστών σε επαγόμενα πολυδύναμα βλαστοκύτταρα (induced pluripotent stem cells, iPSCs) το 2007 άνοιξε το δρόμο για τη μελέτη και την εξατομικευμένη θεραπεία πολλών χρόνιων νόσων. Επιδιώξαμε να δημιουργήσουμε iPS - κυτταρικές σειρές επαναπρογραμματίζοντας μεσεγχυματικά στρωματικά κύτταρα (mesenchymal stromal cells, MSCs) μυελού των οστών, μέσω μιας μεθόδου επαναπρογραμματισμού χωρίς ενσωμάτωση γονιδίων στο γενετικό υλικό των κυττάρων. Δερματικοί ινοβλάστες από φυσιολογικούς δότες και μεσεγχυματικά στρωματικά κύτταρα μυελού των οστών από φυσιολογικό δότη μεταμόσχευσης μυελού των οστών και από ασθενή με β-Μεσογειακή αναιμία (β-ΜΑ) διαμολύνθηκαν, μέσω λιποσωματικών φορέων, με συνθετικά mRNA που κωδικοποιούν τους μεταγραφικούς παράγοντες Oct4, Klf4, Sox2, Lin28, c-Myc. Στη συνέχεια, τα κύτταρα ελέγχθηκαν σε καλλιέργειες για τον σχηματισμό αποικιών πολυδύναμων βλαστοκυττάρων. Οι αποικίες απομονώθηκαν και με συνεχείς ανακαλλιέργειες δημιουργήθηκαν κυτταρικές σειρές, οι οποίες εξετάστηκαν για την πολυδυναμία τους με μεθόδους ανίχνευσης της έκφρασης των μεταγραφικών παραγόντων πολυδυναμίας (κυτταρομετρία ροής, RT-PCR, μελέτη του μεταγραφώματος με RNA μικροσυστοιχίες). Ως θετικός μάρτυρας και μέτρο σύγκρισης χρησιμοποιήθηκε πολύ καλά χαρακτηρισμένη εμβρυονική σειρά πολυδύναμων βλαστοκυττάρων. Οι iPS-κυτταρικές σειρές μελετήθηκαν, επίσης, ως προς τη λειτουργική τους πολυδυναμία με τον έλεγχο της ικανότητας τους να δημιουργούν in vitro εμβρυϊκά σωματίδια και in vivo τερατώματα μετά από υποδόρια εμφύτευση τους σε ανοσοανεπαρκείς ποντικούς, και ως προς τη δυνατότητα διαφοροποίησής τους σε αιμοποιητικά προγονικά κύτταρα. Η γενετική σταθερότητα των κυτταρικών σειρών ελέγχθηκε με DNA μικροσυστοιχίες συγκριτικού γονιδιωματικού υβριδισμού (aCGH). Απομονώθηκαν 3 iPS κυτταρικές σειρές από κάθε δείγμα κυττάρων, οι οποίες εμφανίζουν μεταγράφωμα πανομοιότυπο με εκείνο των πολυδύναμων εμβρυονικών βλαστοκυττάρων και. δημιουργούν εμβρυϊκά σωματίδια in vitro και τερατώματα in vivo, τα οποία αποτελούνται από ιστούς καταγωγής και από τα τρία βλαστικά δέρματα. Τα iPSCs των κυτταρικών σειρών πολλαπλασιάζονται για μεγάλο χρονικό διάστημα χωρίς μορφολογικές ενδείξες διαφοροποίησης. Με τη μέθοδο aCGH, στις iPS κυτταρικές σειρές μετά την 10η ανακαλλιέργεια ανιχνεύθηκαν πολυμορφισμοί στον αριθμό αντιγράφων (CNVs), τα οποία ήταν ελλείμματα μεγέθους περίπου 3 Mb. Η διαφοροποίηση των iPSCs σε αιμοποιητικά προγονικά κύτταρα οδήγησε στην παραγωγή CD34+ κυττάρων σε ποσοστό 8-10% των παραχθέντων κυττάρων με ασθενούς έντασης συνέκφραση του CD45, προσομοιάζοντας στο αιμαγγειακό στελεχιαίο κύτταρο. Στην παρούσα διατριβή παρουσιάζεται, για πρώτη φορά στην Ελλάδα, εξ όσων γνωρίζουμε, η τεχνολογία παραγωγής ανθρώπινων iPSCs με μια ασφαλή και αξιόπιστη μέθοδο. Οι iPSCs-κυτταρικές σειρές μπορεί να χρησιμοποιηθούν στη μελέτη ασθενειών, στον έλεγχο φαρμάκων και στην ανάπτυξη πρωτοκόλλων ιστικής μηχανικής και κυτταρικής θεραπείας.

scholarly journals K+ channel blockade in the NTS alters efficacy of two cardiorespiratory reflexes in vivo

1998 ◽  
Vol 274 (3) ◽  
pp. R677-R685 ◽  
Author(s):  
James W. Butcher ◽  
Julian F. R. Paton
Keyword(s):  
Potassium Channel ◽  
Neuronal Excitability ◽  
Baroreceptor Reflex ◽  
Right Atrial ◽  
K Channel ◽  
Reflex Bradycardia ◽  
Potassium Conductances ◽  
Voltage Dependent

We investigated the role of potassium conductances in the nucleus of the solitary tract (NTS) in determining the efficacy of the baroreceptor and cardiopulmonary reflexes in anesthetized rats. The baroreceptor reflex was elicited with an intravenous injection of phenylephrine to evoke a reflex bradycardia, and the cardiopulmonary reflex was evoked with a right atrial injection of phenylbiguanide. Microinjection of two Ca-dependent potassium channel antagonists (apamin and charybdotoxin) into the NTS potentiated the baroreceptor reflex bradycardia. This may reflect the increased neuronal excitability observed previously in vitro with these blockers. In contrast, the Ca-dependent potassium channel antagonists attenuated the cardiopulmonary reflex, whereas voltage-dependent potassium channel antagonists (4-aminopyridine and dendrotoxin) attenuated both the baro- and cardiopulmonary reflexes when microinjected into the NTS. The possibility that the reflex attenuation observed indicates a predominant distribution of certain potassium channels on γ-aminobutyric acid interneurons is discussed.

scholarly journals Protein Kinase CK2 Controls CaV2.1-Dependent Calcium Currents and Insulin Release in Pancreatic β-cells

2020 ◽  
Vol 21 (13) ◽  
pp. 4668
Author(s):  
Rebecca Scheuer ◽  
Stephan Ernst Philipp ◽  
Alexander Becker ◽  
Lisa Nalbach ◽  
Emmanuel Ampofo ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Calcium Currents ◽  
Insulin Biosynthesis ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Voltage Dependent ◽  
Regulatory Impact ◽  
Kinase Ck2

The regulation of insulin biosynthesis and secretion in pancreatic β-cells is essential for glucose homeostasis in humans. Previous findings point to the highly conserved, ubiquitously expressed serine/threonine kinase CK2 as having a negative regulatory impact on this regulation. In the cell culture model of rat pancreatic β-cells INS-1, insulin secretion is enhanced after CK2 inhibition. This enhancement is preceded by a rise in the cytosolic Ca2+ concentration. Here, we identified the serine residues S2362 and S2364 of the voltage-dependent calcium channel CaV2.1 as targets of CK2 phosphorylation. Furthermore, co-immunoprecipitation experiments revealed that CaV2.1 binds to CK2 in vitro and in vivo. CaV2.1 knockdown experiments showed that the increase in the intracellular Ca2+ concentration, followed by an enhanced insulin secretion upon CK2 inhibition, is due to a Ca2+ influx through CaV2.1 channels. In summary, our results point to a modulating role of CK2 in the CaV2.1-mediated exocytosis of insulin.

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